How to set a custom block page.
Setting a custom block page simply mean replacing our block page with yours. You do this by enabling "Use a custom block page" in your My Account area.
The only caveat here is you can only redirect to the TCP/IP address of the server hosting your block page. So for example, if the TCP/IP address of the server hosting your block page is 18.104.22.168, then you should be able to put that IP into your browser and display your block page.