If you are a team member, you can leave the shared subscription from your subscription settings. The leave option is shown to members, not to the subscription owner.
Leave a team
Go to Settings → Subscription.
Find the Team section.
Click the leave button shown next to your member row.
Confirm that you want to leave the team.
After you leave
Your future downloads no longer use the shared team subscription.
You no longer count against the team seat limit.
The subscription owner still controls the team subscription and billing.
Your Cathopic account remains active.
If your own subscription was paused
When you joined the team, Cathopic may have paused your own active subscription so the shared team subscription would be used instead. When you leave, that paused subscription is resumed and the paid time is preserved by extending the relevant renewal and payment dates by the pause duration.
Joining another team
If you accept an invitation from another team while you already belong to one, Cathopic shows a switch confirmation. Confirming the switch removes you from the current team and joins you to the new one.