You can use the /{environmentId}/as/token endpoint to obtain an access token by presenting its authorization grant. In this activity, the token request identifies authorization_code as the grant type, and it must also provide the code value returned in Step 5.

With the pkceEnforcment property enabled on the application, the token request must provide the code_verifier parameter value. This parameter is used to verify the code_challenge value submitted in the authorization request in Step 2.

The token request transforms the code_verifier property value using the code_challenge_method specified in the authorize request. If the transformed code_verifier value is equal to the code_challenge value submitted in the authorize request, then the authorization server issues the token.