In theory, if you're worried about SIM hijacking, you could use something like Skype SMS, and secure your access to Skype by 2FA on the associated Live account.

In theory, if you're worried about SIM hijacking, you could use something like Skype SMS, and secure your access to Skype by 2FA on the associated Live account. Perhaps there are services to choose from as well, but, I'd take great care in determining trust here.