Ask HN: How to Create DIY MySudo Alternative?

MySudo allows you to create virtual phone numbers so that you never have to give out your SIM card phone number.

Is there a way to do something similar using a VPS and other open source tools? I've been working on self hosting a lot of my services (Nextcloud has been great) and a MySudo alternative would be really great. They've also been iOS only and I'm on LineageOS.