Youtube used to have an opml export button but there are a few github projects that convert the youtube subscription csv that dumps out of the account data export.
Edit: If you want to filter out shorts using the selfhosted application rssbridge allows you to do this.
There are two types of channel RSS feeds
https://www.youtube.com/feeds/videos.xml?channel_id=<CHANNEL_ID>
And the older
https://www.youtube.com/feeds/videos.xml?user=<username>
Youtube used to have an opml export button but there are a few github projects that convert the youtube subscription csv that dumps out of the account data export.
Edit: If you want to filter out shorts using the selfhosted application rssbridge allows you to do this.