To create a user license based subscription model, you can couple a quantity-based recurring addon with a base plan.
First, create a flat-fee based plan with a fixed base fee if applicable. If there’s no base fee involved, you can set the plan’s price to $0. This will be used to create the subscription for the customer.
Next, create a recurring quantity based addon(set the 'Pricing Model' as 'Per Unit') for the users/licenses set the price of each user/license as the unit quantity price of the addon.
You can also configure Volume-based or Tier-based pricing model for the addon. Here’s more on that.
Based on the customer’s quantity or the number of licenses they select, the appropriate quantity of the addon can be added to the subscription when it’s being created or edited.
Selecting quantity on the latest Checkout pages(V3):
The addons that the user selects needs to be passed to the checkout page from your end. Refer to this solution article for the details. To configure the checkout pages (V3) through APIs, refer to this link.
The feature to select quantity based addons in the new checkout version will be rolled in the upcoming iterations.
Selecting quantity on the checkout pages(V2):
If you're using our V2 hosted pages for signing up, you'd need to capture the license quantity and pass the addon and its quantity through the hosted page URL. Here’s more on this.
Related articles and documentation:
How to pass addons through Checkout V2?