I’m using OAuth2 Authorization code flow, the initial authorization works fine, I get the access code and refresh token and API works as expected. Scopes are set to smartlock smartlock.auth.
When the token expires, I try to refresh the token, which fails with a 400
{"error":"invalid_grant","error_description":"The provided authorization grant (e.g., authorization code, resource owner credentials) or refresh token is invalid, expired, revoked, does not match the redirection URI used in the authorization request, or was issued to another client. The refresh token has not been found: not_found"}
Nevermind, I figured it out.
Please add to the documentation that when refreshing the access token, the refresh token is also being refreshed with it.