Once you've created or joined a universal channel in Microsoft Teams, you may want to do things like:
View external members in the channel
Find the channel's invite link to invite more members
Deactivate the channel (only if you have permission to do so)
The important thing to know is that you don't need to talk to the Mio app directly in the channel. That would be noisy for other members!
Instead, use the Mio app extension.
At the bottom of any channel, find the · · · and select Mio.
Don't see the app? Make sure the Mio app is installed in that channel's team.
From here, you can
Copy channel's invite link
View your channel's member list
View the channel's owner
Send an email invite to a contact who hasn't joined yet