Accidently left team while trying to terminate subscription

Hey ​@Mina.Atef, thanks for reaching out! 

Just a heads-up, only team admins or owners can downgrade a Professional team. If you’re no longer part of the team, you’ll need to reach out to the current team admin or owner and ask them to downgrade the plan.

Or alternatively you can rejoin the team first by asking someone who has can edit team permissions to invite you back with can edit or can view team permissions:
https://help.figma.com/hc/en-us/articles/360039481034-Invite-team-members. 

Once you’re back on the team, you can ask the current owner to transfer ownership to you so you can downgrade the team by yourself. More details on that process here:
https://help.figma.com/hc/en-us/articles/360039481134-Transfer-ownership-of-a-team. 

To cancel your Professional plan subscription:

1. Using the browser or Figma desktop app, locate the Professional team in the file browser sidebar.
2. Click  Admin.
3. Select the  Settings tab.
4. In the Plan section, click Cancel plan.
5. Figma will ask you for a cancellation reason. Select the most appropriate reason and click Cancel plan.

At the end of your billing period, Figma will downgrade your team to a free Starter team. Any seats you add before your plan is downgraded will be prorated and reflected on your last invoice. You’ll have access to all Professional plan features until the end of the current billing period.

Find more information in our Help Center article: Downgrade or cancel your plan

Hope this helps, please let me know if something is unclear!