How can we add this plugin to the download collection on the official page? |
By "official page", do you mean inside the Lightroom application itself? If so, you'll have to contact Adobe directly about that. (Adobe product developers don't participate in this forum.)
If you mean the Adobe Add-ons site, click on "Go to the producer portal" in the lower-left corner of the Add-ons home page. Beware that Adobe has announced they'll soon be replacing the current Add-ons store with a new "Adobe Exchange" (not to be confused with the old Adobe Exchange of a few years ago). Also beware that the most-used LR plugins are not distributed through the current Adobe Add-ons site, which isn't well-integrated with LR. Maybe that will change with the "new" Adobe Exchange.