How to resolve 'other party is offline' error in Apple Watch Walkie-Talkie?

Hello. My friend and I both have the Apple Watches. We tried to send one another invites and it didn’t work. After 2 days of trying .. I finally got her invite and accepted .

but we never were able to connect to one another as in everytime she or I try to connect ..

we get the error message that the other party is offline .

even when we are standing next to one another . It says the same error message. Please help. Thank you

[Re-Titled by Moderator]

Original Title: Apple Watch walkie