Controlling settings, permissions, and membership within Teams and channels
Hi Trina,
My name is Didi. I'm happy to help you today.
'Shared channel' is available in Public Preview. If Public Preview is enabled in your organization, and you're a team owner, could you try clicking on the ellipsis beside your profile photo > About > Public Preview > Switch to public preview
Then try signing out or refreshing your screen to see if you'd be able to create a shared channel
For more information on shared channels, you may visit:
https://support.microsoft.com/en-us/office/crea...
I hope this helps.
Best regards,