@altstore I paid, got to a download page (in Firefox), clicked the "marketplace-kit://" link, invited to "open this link in external app?" Clicked "OK". Nothing happens. Tried the same page in Safari, also got to download page, this time I clicked the link and nothing at all happens.

I went to your page to find how to contact support, and the options are "business inquiries", "press" and "developers". So I guess social media is the only option?