Jici
8
Could be two thing. A) You are not getting the code from the page url.
From what I see, this may be possible as you try to use open an external website that is probably the authorize url and after in the same workflow, you are trying to fetch the token.
You should remove all step after open an externa website (that is probably returning an error in issue checker anyway because this should be the last step in a workflow) and instead add a workflow on page load (when get code from page url is not empty) and process to the continue step.