curl --request POST \
  --url https://sandbox.ntxpay.com/api/auth/token \
  --header 'Content-Type: application/json' \
  --header 'X-SSL-Client-Cert: <api-key>' \
  --data '
{
  "clientId": "qr-93-550e8400",
  "clientSecret": "a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6"
}
'

{
  "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 600,
  "scope": "email profile"
}