Ask for a phone number!
At this time, Threads requires that you have a phone number for people that you’d like to connect with on the app. We do recognize that there are some important people in our lives who we connect mostly with on other social and messaging platforms, and for whom we may not have a phone number for at the moment.
We recommend that you use your regular connection tools (Facebook Messenger, Insta DM, iMessage, WhatsApp, etc.) to ask for their mobile phone number, so you can connect with them on Threads, too.
Once you have a phone number for them:
Add them to your device contacts.
Open your Threads app.
Invite them to connect with you by sending them a Moment, Check-in, Thread Starter, or an invitation from the “My People” screen.