Getting a token in an api

I would like to perform operations within my api (nestjs) such as creating users in my Auth0 account.

I do it using the instruction
this.httpService.post(this.auth0_user_path,newUser, { headers: headersRequest })
where auth0_user_path contains the url ending in “/users”, newUser contains the new user’s data, and headersRequest, contains among other things the token I generated from postman.

To generate this token from postman, I have used the Auth0 Management API parameters (client_id, client secret, etc…) and as grant_type: client credential.

I introduce the token generated from postman in headersRequest and the new user is created perfectly.

Now I would like to generate the token from my api. To do this, I use the instruction
this.httpService.post(this.auth0_token_path,{ data: dataRequest }, { headers: headerRequest })
where auth0_token_path is the Auth0 Management API path ending in “/oauth/token”, dataRequest contains the client_id data, client secret, grant_type=client_credentials.

Token generation fails due to authorization denied.

What should I do wrong, use client_credential?
Is there any documentation that can help me?

Thanks

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