Individual customer files with certificate expiry emails on Debian

Dear Debian community,
Is it possible with Debian to set up a system similar to Moodle, where I can place individual files for each person? In those files, they could view (or download) their certificates, and they should also automatically receive an email with the expiration date of that certificate.
Specifically for my work as an HVAC technician: I would like to create a small digital file for each customer. The customer can then log in remotely using a personal code to view their own file. The entire process should be digital and automated.
Thank you in advance for your advice!
Best regards,
Bart Bracqué