Used the token, received after giving consent on the API explorer.
error: "internal_server_error" reference_id: "a9291605-10a3-4674-9a76-219d56f6dd07"
I have checked the integrator key which has been used, the Authorization Code Grant is enabled on it. What I might be doing wrong?
Edit -
The error I had was that the OAuth 2.0 flow, I used the Implicit Code Grant and it worked.