There's some more pertinent information in
the eBay description which I think will answer all your questions, including that the description mentions that "It is a
spec script for an episode that was never filmed!" and "THIS AUCTION COMES WITH THE REJECTION LETTER FROM THE STUDIO INDICATING THAT THE STORY WAS NOT BEING PURCHASED." There are also some photos of the script pages, which show it has some copy-editing errors and style variations from an actual script for the show. It was written by (Jeffrey) Scott Kindred, who has a couple credits on IMDB, but no official connection to Star Trek. It was written by someone with no connection in the show, who sent it to the production team in hopes of them buying it or inviting him to pitch other story premises they might buy or commission from him.
There are thousands of unsolicited scripts and pitches like this from the '90s Trek shows (or any show, really, but Trek would occasionally actually buy scripts like this, rather than them just serving as portfolio pieces for new writers who didn't yet have anything that had actually been filmed that they could point to as an example of their writing ability).
So, TL;DR, no, no one is going to have a PDF of this script, possibly including Scott Kindred himself. It's more-or-less an unpublished fanfic. Maybe interesting, but there are many other (and, no shade, probably better) examples of stories sent in during Trek's open-submission era for scripts that writers have posted themselves on-line, including several members of this board.
(Mods, if linking to the auction violates the non-solicitation rules, feel free to edit it out, but from stuff like the Set Blueprints thread in Trek Art, I'm pretty sure linking to something I'm not selling or recommending people buy just for informational purposes is okay.)