I am using a lambda function URL that looks something like this...
https://xxx.lambda-url.us-east-1.on.aws/?test this
This is working as expected (actually awesome!)
But it fails if the user types / or , and it does not submit the text after #
I can replace these three characters with space and the problem is solved. But are there any other characters I need to take care of?
(app developed using kotlin if that matters)
Yes you need to 'percent encode it' or 'url encode it'. If you're generating the URL in javascript you can use the URL object or encodeURIComponent().
As a general rule in programming, whenever you generate a string that has some kind of format, you should always ask: "What is the escaping mechanism". Failing to do so can result in bugs and big security problems.