Sorry for the very late reply.
I see that you are getting a Redirect error.
I had already closed the app for myself, but I connected the GitHub source code and deployed in Digital Ocean again.
In the process, I got an Invalid Client Error when I tried to add the Integration App to Fibery without setting the Client ID and Client Secret to environment variables in the Digital Ocean configuration screen.
(In the video below, I also set ENV_TEST_TOKEN, but the app worked without it)
Is this different from the redirect error you are facing?
Fibery - Todoist Integration Setup Demo - Watch Video
The Todoist Client ID and Client Secret were obtained by creating an app in Todoist (see image below).
I just showed you that the app works properly with my settings.
However, considering making this available to others, I may have to do it on the Todoist side as well, as there is a page to Submit the app. But any more than this is technically out of my hands, sorry.
If I have not been able to solve any of the problems you are facing, I hope other engineers can help.
As mentioned even recently in a topic here, the development of integration features does not seem to be a high priority…
Of course, I understand that it is inevitable since their resources are limited!
But it would be really nice if a diverse set of integrations existed
If you could host the Todoist app, that would be really great!