You can manage your Auth0 subscription plan from the Auth0 Dashboard.
Go to Dashboard > Settings.
Select the Subscription tab. You have the option to pay on a monthly or yearly basis.
You can upgrade your subscription from a Starter plan to an Essentials or a Professional plan or from an Essentials to a Professional. To upgrade to an Enterprise plan, contact Auth0 Sales.
On the Subscription tab, scroll to the panels describing the plan options.
Select a new plan and click Checkout to upgrade. If you do not have your billing information stored with Auth0 you'll need to provide it.
Click Subscribe Now to confirm your information and activate your new subscription.
Downgrade to a Starter subscription
On the Subscription tab, scroll to the box associated with the Starter plan and click Checkout.
To confirm your subscription change, click Subscribe Now.