Hello, thanks for your reply.
The plugin isn't followed as you say, the update was for an issue I reported.
However in WHMCS the main feature is recurring billing.
This addon doesn't support it, i opened a ticket back in 2020 and it's still not being developed (I replied the ticket multiple times) multiple times they said me that it will be developed in the next week and it has never been done.
That's why I want an official integration instead.