Regarding changing the payment method

Hi there, Thanks for reaching out about this!

You can add full seats to the team’s annual subscription from:
the team “Settings” tab, under “Plan and billing” > “Add additional seats.”

“Add additional seats” is only shown if you have more editors on your team than are already on your annual subscription. At this time, you can only convert the number of editors you have on a monthly plan.

However, our support team can assist you in manually adjusting the number of editors.
If you’d like to adjust, please reach out to our support team using this link: https://help.figma.com/hc/en-us/requests/new?ticket_form_id=9707134248215
When contacting us, please make sure to use the email address associated with your Figma account.

This addition will be billed on your next monthly billing date, as noted on that modal. Once payment is complete, an invoice will be available for that charge on your Billing tab as usual.

Please refer to our Help Center article for further details at: Add, manage, or renew annual subscriptions

Hope it helps!
Thanks again for reaching out.