Getting error during authentication

I am able to authorize and get a code for my client.
But when I try to authenticate getting
error: "invalid_grant"
error_description: “Redirect URI mismatch.”

Any idea why I getting this?

I using this url to make the request through a Chrome rest client

Does the redirect_ui need to match the one you used for the first call (to get the code)? I’m not sure, but that seems like what the error is suggesting.