The app (tested on Android only) seems unable to handle links shared to it. Namely, if the string contains not a bare URL but includes with it the heading text of the article, then the app won't work. I presume it always expects a URL only, though it only gives a generic error message: "An error occurred, please try again later".
Some apps (e.g. FeedMe) prepend the heading of the article with the url when you share them. For example:
"Will factory farming fix itself? https://www.worksinprogress.news/p/will-factory-farming-fix-itself"
Web browsers and other apps (e.g. paper2audio) are able to handle such strings without issue. So it would be nice to have this work seamlessly. Currently I have to share the link to Firefox first, then from Firefox share it to the Kagi app.
Parse the URL from a string that contains both a URL and text.