Why do I get Unknown Application

OcelotBOT is an old bot, it was made before Discord added bot accounts. This means that the client ID and user ID are different.
A lot of bot lists assume that these values are always the same, so when OcelotBOT is added, the invite link won't work unless it's changed manually.

HERE is an invite link that works
If you're just looking for the client ID, it's 171640650721132544.

FAQ

Why can't you just use the client ID when submitting the bot?

The client ID is not a user account, your bot list backend will not recognise it as a valid bot. It will only recognise the user ID.

How can I fix this?

The best way to fix this would be to allow custom invites to be entered. Failing that, allow for an optional client ID box.