curl --request POST \
  --url https://api.sx.bet/user/multisig/add-signer/execute \
  --header 'Content-Type: application/json' \
  --header 'x-sx-api-key: <api-key>' \
  --data '
{
  "safeAddress": "0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8",
  "safeTxHash": "0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7",
  "safeTransactionData": {
    "to": "0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A",
    "value": "0",
    "data": "0x",
    "operation": 0,
    "nonce": 3
  },
  "signature": "0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab",
  "signerAddress": "0x52adf738AAD93c31f798a30b2C74D658e1E9a562"
}
'

import requests

url = "https://api.sx.bet/user/multisig/add-signer/execute"

payload = {
    "safeAddress": "0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8",
    "safeTxHash": "0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7",
    "safeTransactionData": {
        "to": "0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A",
        "value": "0",
        "data": "0x",
        "operation": 0,
        "nonce": 3
    },
    "signature": "0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab",
    "signerAddress": "0x52adf738AAD93c31f798a30b2C74D658e1E9a562"
}
headers = {
    "x-sx-api-key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'x-sx-api-key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    safeAddress: '0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8',
    safeTxHash: '0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7',
    safeTransactionData: {
      to: '0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A',
      value: '0',
      data: '0x',
      operation: 0,
      nonce: 3
    },
    signature: '0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab',
    signerAddress: '0x52adf738AAD93c31f798a30b2C74D658e1E9a562'
  })
};

fetch('https://api.sx.bet/user/multisig/add-signer/execute', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.sx.bet/user/multisig/add-signer/execute",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'safeAddress' => '0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8',
    'safeTxHash' => '0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7',
    'safeTransactionData' => [
        'to' => '0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A',
        'value' => '0',
        'data' => '0x',
        'operation' => 0,
        'nonce' => 3
    ],
    'signature' => '0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab',
    'signerAddress' => '0x52adf738AAD93c31f798a30b2C74D658e1E9a562'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "x-sx-api-key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.sx.bet/user/multisig/add-signer/execute"

	payload := strings.NewReader("{\n  \"safeAddress\": \"0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8\",\n  \"safeTxHash\": \"0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7\",\n  \"safeTransactionData\": {\n    \"to\": \"0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A\",\n    \"value\": \"0\",\n    \"data\": \"0x\",\n    \"operation\": 0,\n    \"nonce\": 3\n  },\n  \"signature\": \"0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab\",\n  \"signerAddress\": \"0x52adf738AAD93c31f798a30b2C74D658e1E9a562\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("x-sx-api-key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.sx.bet/user/multisig/add-signer/execute")
  .header("x-sx-api-key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"safeAddress\": \"0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8\",\n  \"safeTxHash\": \"0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7\",\n  \"safeTransactionData\": {\n    \"to\": \"0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A\",\n    \"value\": \"0\",\n    \"data\": \"0x\",\n    \"operation\": 0,\n    \"nonce\": 3\n  },\n  \"signature\": \"0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab\",\n  \"signerAddress\": \"0x52adf738AAD93c31f798a30b2C74D658e1E9a562\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.sx.bet/user/multisig/add-signer/execute")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["x-sx-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"safeAddress\": \"0x8E4c91A7D2b0f35e6A19c84d70B2e5F1a3c6D9e8\",\n  \"safeTxHash\": \"0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7\",\n  \"safeTransactionData\": {\n    \"to\": \"0x4361123dbdc1D812fdf7D27045aF358C9C8AA70A\",\n    \"value\": \"0\",\n    \"data\": \"0x\",\n    \"operation\": 0,\n    \"nonce\": 3\n  },\n  \"signature\": \"0xababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababababab\",\n  \"signerAddress\": \"0x52adf738AAD93c31f798a30b2C74D658e1E9a562\"\n}"

response = http.request(request)
puts response.read_body

{
  "status": "success",
  "data": {
    "safeTxHash": "0x9c8f5b21e4d0a7c3f18b6e94d2a05c7318fa4b62d9e0173c5a8b2f4e6019d3c7",
    "confirmedBy": [
      "0x52adf738AAD93c31f798a30b2C74D658e1E9a562"
    ],
    "signedCount": 1,
    "requiredThreshold": 1,
    "isReadyToExecute": true,
    "isExecuted": false,
    "executionTxHash": null
  }
}

{
  "message": "signerAddress must match the authenticated address",
  "error": "Bad Request",
  "statusCode": 400
}

{
  "message": "BAD_AUTH",
  "error": "Unauthorized",
  "statusCode": 401
}

{
  "message": "the target Safe is not associated with your account",
  "error": "Forbidden",
  "statusCode": 403
}

{
  "message": "your proxy wallet is not deployed yet",
  "error": "Conflict",
  "statusCode": 409
}