A software solution might be twilio. Just set up a SMS to email gateway with them. That being said, a “shared” second factor is not a good idea and neither is

A software solution might be twilio. Just set up a SMS to email gateway with them. That being said, a “shared” second factor is not a good idea and neither is the use of SMS as second factor. This is because an attacker could use a sim swap attack or a S7 attack. Also, you might lose your number for a reason outside of your control. That being said, you might want to look into an Authenticator (OTP) app (Google, Authy, ...) or a Hardware token like YuhiKey for your needs.