There is currently no way to delete a custom EasyApache 4 profile via WHM.
Fortunately, they're easy enough to remove via SSH by navigating to the /etc/cpanel/ea4/profiles/custom/
directory where you'll see a list of custom profiles:
[root@techno ~]# ls /etc/cpanel/ea4/profiles/custom
example_custom_profile.json
[root@techno ~]#
You'll need to inspect the contents of the file in question to ensure you're deleting the intended profile, then run:
rm /etc/cpanel/ea4/profiles/custom/example_custom_profile.json