Step 1: Go to Cloudflare Website and Login Your Account.
Step 2: Click on the Domain Which You Want to Remove From Cloudflare.
Step 3: At the Cloudflare Overview Page, Navigate Down and Look For Advanced Options In the Sidebar.
Step 4: Now After Scrolling Down You’ll See the Advanced Options at the Sidebar.
Step 5: Click the Remove Site from Cloudflare Option.
Advanced Actions
Pause Cloudflare on Site
Remove Site from Cloudflare
blog:Steps For How to Delete a Site/Removing a Domain from Cloudflare?
https://letsmakeiteasy.tech/how-to-delete-a-site-removing-a-domain-from-cloudflare/