I don’t use AWS, but block access to our instance using firewall rules to filter out IPs, not on an approved list. Not sure what AWS offers in terms of firewall support.
I am using PFSense, and it can pull a list of IPs from a URL at an interval. I have scripts that create the approved IP list for PFsense to pull. IPs on the list make it to the forum, IPs not on the list are redirected to a page explaining the block.
I use this same technique to block access to Atlassian Confluence instance. Since it’s a firewall rule you can block any type of traffic you want, to any destination you want. Very flexible.