Thanks for your feedback.
Unfortunately, it looks like they changed their policy on when to require a captcha and I don't see a way to get around this anymore 
I currently don't have a good way to inform about this in the app and I'm not sure what would be the best way here: keeping it like it is now or removing native support for PostIT and only only displaying their website in the app (where you'd have to solve the captcha every time)