Modal for a Wordpress site to integrate with Stripe Subscriptions

We are looking for a custom integration of a Wordpress site (using Elementor) with Stripe Subscriptions with multiple payment plans. Please provide examples of your work with Stripe Subscriptions and your understanding of what multiple plans per a single subscription means. Feature Requirements - From our site, a user will click on a purchase button - There are multiple buttons to click on: Monthly Premium, Quarterly Premium, Monthly Plus, Quarterly Plus - When you click on a button a modal will display with pre-selected options depending on which of the 4 buttons you clicked on - User can change selection in the modal - Modal is basically a checkout form with our logo at the top, form with options and subscribe button at the bottom (I will provide a mockup) - Within the modal there will be additional options for add-on subscriptions - Each of the options and the add-ons are separate subscription plans within a subscription product - As the user makes selections on the modal, the modal will show a new total price for the subscription - The modal will need to integrate with Stripe API to subscribe the user with the correct subscription and the correct pricing plans Technical Requirements - All of the code must be heavily documented and commented - Modal code should be separated into a plugin so we can keep the code separate and can easily access it and also allow us to modify our theme and still be able to use the code - Modal should easily be called from a button