Technically there are websites that will hurt your chances of applying for monetization, but they don't a special list of them.
Patreon, Discord and Merch are all safe to use.
Illiegal sites such as those that distribute illegal software, scamming software, websites that have viruses and such to download, adult websites and such are obviously not allowed.
But for the most part, as long as the website isn't a scam and is a trusts resource, it's safe to use.
Just don't use TOO MANY outside links. Every link you add to your descriptions that aren't a video link taking you to another video on YouTube, is a session ending link that takes you away from YouTube. Do THAT too often and it may harm your chances. There's nothing specifically mentioning that, but if your video descriptions are littered full of links they may see that as "spam links" and that will probably hurt your chances as people that review your channel for monetisation don't just look at your videos and thumbnails, they CAN look at your descriptions too to make sure your links are safe and not spamming your description.
Basically if it's a link you'd feel safe sending your Grandparents or Boss to, you'll be ok. just don't go overboard with links.