You can manage the subscription for an individual workspace directly from the mobile app settings.
Open Settings/Profile.
Find Billing details.
Select the workspace whose subscription should be managed.
Open Subscription to change the billing period or credit tier.
Note: You can choose between Monthly, Tri-Monthly, and Annual billing.
Available credit tiers are 150, 300, 500, 700, and 900 monthly credits, with 900 being the highest plan currently offered on mobile due to App Store and Google Play policies.