I tested it out an I have no options to click to accept the cert. This is in macOS 10.15.x with up-to-date Safari.
From this article it looks like Safari just gives a middle finger and tell you to have the admin fix the server.
That isn't a fix for developers. How about a means to disable the cert check with "developer mode".
Louis L'Amour, “To make democracy work, we must be a nation of participants, not simply observers.
One who does not vote has no right to complain.”
Visit our archived Minecraft world! | Maybe someday I'll proof read, until then deal with it.