Encountering Issues When Calling Freshsales APIs with OAuth Access Token

I am currently implementing the OAuth 2.0 authorization flow in an external application to access Freshsales resources. While I have successfully obtained an access token, I am encountering an issue when attempting to make an API call. I would greatly appreciate your guidance on this matter.

A sample response of authorization and get access token is as follows:

{"access_token": "fwoauth_eyJraWQiOiI4NzY0MjUyMzUXXX....","refresh_token": "vZUjvmzgUC8cMxDQVs7BX3z3RiiGoW6XXX...","scope": "freshsales.contacts.create freshsales.contacts.upsert freshsales.lookup.search ...","token_type": "Bearer","expires_in": 1799}

API call for create contact :

curl -X POST "https://abc1-876425233515354960.myfreshworks.com/crm/sales/api/contacts" \
-H "Authorization: Bearer <access_token>" \
-H "Content-Type: application/json" \
-d '{
"contact": {
  "first_name": "James 123456",
  "last_name": "Sampleton (sample)",
  "mobile_number": "1-926-555-9503",
  "email": "james.sampleton@example.com"
}
}'

Response For that :

{  "login": "failed",  "message": "null",}

Any guidance, documentation, or examples to correctly perform contact creation via the API following OAuth authentication would be highly appreciated.

@Freddy Help me to find a solution :neutral_face: