I'm not familiar with Pikapods but Monica v4 has trouble with notifications. First you need to ensure it's been configured right to even send a test email, this can be triggered with a command if you have access:

php artisan monica:test-email

Various Monica environment variables must be set to configure this, it should be in the docs somewhere if not I can fish my config out for you.

Even once that's working you'll need Monica to run its regular jobs for sending notifications, there's config for that too. Finally the code has bugs and will often miss reminders in my experience. There are some open bugs still on this and I guess the devs have moved onto their rewritten version (chandler):

https://github.com/monicahq/monica/issues/5681

The documentation says it's possible to send test notification:

That whole notification section is not familiar at all. There is current work to completely redo Monica and when I view their beta at https://beta.monicahq.com/ then it seems to reflect that new version. So I suspect that documentation is wrong for the current version (which hasn't been meaningfully updated in years).

In addition to what rhe other user asked, what do logs say, how are you configuring emails?

Email notification and the like usually don't work out of the box and require SMTP configuration. This is usually available in the app admin consoles or configurable through Environment variables in the console.

I'm not running it ( and I haven't checked it for Monica HQ ), but those would be the first things I'd look for.

The .env.example file shows SMTP settings. The example file notifies to a logfile rather than an email.

https://github.com/monicahq/monica/blob/main/.env.example

# Mailing
# Set the MAIL_MAILER to 'smtp' if you want to send emails.
MAIL_MAILER=log
MAIL_HOST=smtp.mailtrap.io
MAIL_PORT=2525
MAIL_USERNAME=null
MAIL_PASSWORD=null
MAIL_ENCRYPTION=null
MAIL_FROM_ADDRESS=hello@example.com
MAIL_FROM_NAME="${APP_NAME}"
MAIL_REPLY_TO_ADDRESS=hello@example.com
MAIL_REPLY_TO_NAME="${APP_NAME}"

Have you checked with the pikapod support team and/or help pages? They've really helped me it in the past.

https://docs.pikapods.com/apps/monica

Does that help, for instance?

Anything in the logs?