I am new to this, and maybe I am getting something wrong.
I made an account in a certain peertube instance, but when I search online and there is a peertube video, it opens on their instance, where I have no account for commenting, and also there is for example no dark theme… so is there an option to automatically open these links through my desired peertube instance?
There is currently no way to automatically open links through your PeerTube instance, because this pertains to how your browser knows they should be redirected and where. This is a complex problem, and unless a browser plugin comes to help with it, we have no way of implementing that.
The problem is explained in-depth at https://socialhub.activitypub.rocks/t/represent-endpoint-for-remote-interaction/480
This is currently discussed in https://socialhub.activitypub.rocks/t/suggestion-a-custom-url-scheme-handler-as-a-streamlined-ux-for-cross-instance-interactions-on-the-web/504
Until there is a solution, you can copy/paste the url of the video in your instance’s search bar. It will open it directly in your instance, so you can comment and do some other stuffs.
NB: the instance admin can disable this feature, so if it does not work on yours…