How to implement donation access in Google Chrome extension?

Question

Browser extensions

It is necessary that when downloading the extension and clicking on it, a window appears with a choice - pay online or enter the registration code. When you clicked on pay online, there was the following window with a choice of 1 day, week or month. Accordingly, when clicked, it would be sent to the payment site and after successful payment, it would open for the number of paid days.
When you click on the registration code, key 1 would come out (for each user its own)
And key 2 - when you enter it, it would let you into the application (again, for 1 day, week or month)
I see it like this. I am ready to consider other implementations and ideas for paying for access to the extension for a certain period.