Authorization

OkHttpClient client = new OkHttpClient().newBuilder()
  .build();
MediaType mediaType = MediaType.parse("application/x-www-form-urlencoded");
RequestBody body = RequestBody.create(mediaType, "client_id=Your Client ID&client_secret=Your Client Secret&grant_type=client_credentials&scope=default");
Request request = new Request.Builder()
  .url("https://auth.gopay.mn/oauth/token")
  .method("POST", body)
  .addHeader("Content-Type", "application/x-www-form-urlencoded")
  .build();
Response response = client.newCall(request).execute();

const axios = require("axios");
const qs = require("qs");
let data = qs.stringify({
  client_id: "your client id",
  client_secret: "your client secret",
  grant_type: "client_credentials",
  scope: "default",
});

let config = {
  method: "post",
  maxBodyLength: Infinity,
  url: "https://auth.gopay.mn/oauth/token",
  headers: {
    "Content-Type": "application/x-www-form-urlencoded",
  },
  data: data,
};

axios
  .request(config)
  .then((response) => {
    console.log(JSON.stringify(response.data));
  })
  .catch((error) => {
    console.log(error);
  });

<?php
$client = new Client();
$headers = [
  'Content-Type' => 'application/x-www-form-urlencoded'
];
$options = [
'form_params' => [
  'client_id' => 'client1',
  'client_secret' => 'clientsecret1',
  'grant_type' => 'client_credentials',
  'scope' => 'default'
]];
$request = new Request('POST', 'https://auth.gopay.mn/oauth/token', $headers);
$res = $client->sendAsync($request, $options)->wait();
echo $res->getBody();

curl -L -X POST 'https://auth.gopay.mn/oauth/token' -H 'Content-Type: application/x-www-form-urlencoded' -d 'client_id=your client id' -d 'client_secret=your client secret' -d 'grant_type=client_credentials' -d 'scope=default'