[ale] Simple online calendar program for Apache?

[Bob Toxen]

Can anyone recommend a SIMPLE online calendar program
that works on Apache on Linux without any extra requrements?

Our club just wants a member to say "I want to reserve the
clubhouse on, say, 11/15/2022 from 6 pm to 9 pm and then
send mail to members and show it on a calendar page.  We
don't need a lot of security, perhaps a simple password to
reserve it with a hint.

(No, I don't want Facebook or Google spying on us.)

THANKS,
Bob