Zoho CRM API Error AUTHENTICATION_FAILURE "Authentication failed"

Zoho CRM API Error AUTHENTICATION_FAILURE "Authentication failed"

ZOHO API
Self Client creation
Scope
ZohoCRM.settings.modules.all,ZohoCRM.org.all,ZohoCRM.users.all
generates code

Using Postman
POST request generates access token
{
    "access_token": "1000.b9f0a851ae0007e64d7d071d30428100.845831454fee79cfac0da06d7813e276",
    "refresh_token": "1000.d1be66cdd11d3fec1f0406100aded4bf.2f78f9146b0ce060cfdb774fb626e480",
    "api_domain": "https://www.zohoapis.eu",
    "token_type": "Bearer",
    "expires_in": 3600
}

Get modules generates authentication error

{"code":"AUTHENTICATION_FAILURE","details":{},"message":"Authentication failed","status":"error"} 

Get roles generates authentication error
oauthtoken=1000.16850a016c0749de234cffa138205835.3cf97d7bbd672c2893cb4d4753d99c3a

{
    "code": "AUTHENTICATION_FAILURE",
    "details": {},
    "message": "Authentication failed",
    "status": "error"
}

tried postman call and curl call , tried different urls for example crmsandbox.zoho.com/ and www.zohoapis.com but I always get an Authentication failed error, I am aware that the self client code has limited validity of 10 minutes maximum

How to solve, in Zoho CRM Developer Space web apps / add client id i get message " user is not org admin "

How to assign superuser rights to my user account?

We want to integrate chat bot software with zoho crm via webhooks ( perhaps also using zapier software ) to generate a lead in Zoho CRM from a chatbot contact form communication.

Can you please respond by providing detailed work instruction on how to solve, so I can contact my manager on how my manager has to assign specific user roles to my account to solve this.

thank you.