Hi there!
Taiga is a Project Management software focused on Agile and multidisciplinary teams. Github is a git forge for code versioning and management, so at their core they are pretty different products.
That said, we do have an importer, which imports your issues from Github into Taiga issues, and we do have a one-way integration from Github to Taiga which allows issues created on Github to be then created on Taiga, adding comments to those issues and changing the status of an epic/user story/issue with a commit message. Changes from Taiga are not propagated to Github.
Now as for your issue with the setup, you should not need to touch the conf.json file unless you require specific mappings of different settings than the one’s provided. The importer can be enabled just using environment variables: Taiga 30min Setup. That is for the importer, so when you create a new project. Follow all the steps there, including how to create an Oauth Client id.
The integration needs to be enabled per project, as it is different from the importer.
Hope this helps.
Best regards!