i have not used the phone # on telegram nor have i entered a 1 before the #. i can pull the sim card and use it on an android phone to install telegram if adding the 1 does not work.
@dr1445 If you and your family have a Matrix account (or set one up here: https://riot.im/app/# (name and password required)) then this uMatriks app has VoIP calls: https://open-store.io/app/umatriks.mariogrip.test
(open source all the way! )