Could not configured connector Incoming Webhooks

I tried a lot of time and also review many answers but I could not found any answer for it.

In many answers, it starts working automatically so I am surprised.

While adding the incoming webhook, I could not generate the link, rather it gives me the below error.

I also checked the permission to allow Add, Edit incoming webhook in Settings --> Permission.

I tried both the way, by giving permission and by removing the permission, but every time it gives me the same error. "Something Went Wrong"