Migrating between Gitea and GitLab is not straightforward, seeing as they do not provide any import/export functionality which is baked in and compatible.
I created a script which you can find here: https://zxq.co/zxq/malcolmx/-/tree/master/migrate It migrates:
The script works by acting directly on the Gitea database (thus prone to break following changes to the schema), is not really well-polished and contains some hard coded configuration. But in general it provides a base to hack on for anyone wanting to do this. As a general tip, it might be useful to just grep for Getenv to get configuration variables, zxq.co to get hard-coded urls.
If this saved you a couple of days’ work: have fun!