New tabs opens fine. Now I see there are a working alternative links on patreon page, not sure if they were before. I remember clicking download now, going to patreon page, in list of mods clicking on "Preteens" that opening itch.io where I clicking "download" that opening patreon page and a couple cycles more I understand that something wrong. If there were a links before on patreon page, and its was me who overlooked, still popup "download should start momentarily" really not helping and created this confusion.
On ItchApp clicking install giving just errors:
Viewing post in Download button not working
I guess that the dev did use that download button "creativly". I recently did saw an external link that did open the download dialog of the browser directly. But most of the time it is just the respective file hoster's page that opens.
There is no payment active, but if it were, itch would expect the download button to lead to an actual singular download. But even without payment, it is a statistic thing. The dev might have a counter of downloads from itch. I do not know, if the dev could distinguish from where the traffic comes, if the files are on a file hoster.