Step by step:
In your Webex spaces, find the direct message with the Mio bot. Type and send "create".
Select New space and then Continue →.
Type in your desired channel name and select Create channel →.
You should see a notification from the new universal channel you created.
That's it! You have successfully created your first universal channel!
Finding the invite link later
If you need to retrieve an invite link to a specific universal channel, go back to the Mio bot and type and send "invite".
You'll be given a drop down list of all the universal channels you created. Select the channel you're looking for.