Do you really think a site where we are lucky enough to have professional Trek authors participate is a suitable place to try to undermine their ability to earn a living ?
Some libraries have ebook lending, otherwise there's always second hand on places like Amazon if you're cash-strapped.
"Hello, police department? Who do I need to speak to about someone stealing my drugs? Not all of them, of course; I still have tons of narcotics laying around my house. Oh, so you can help. Great."
Libraries with e-book sharing are the only places to do it legally, and nobody on here is going to help you get them illegally.
I'll cut the guy a break and assume he means legitimate ways to read Star Trek literature. But Kataaran and JD probably have the best suggestion, the local library. I don't think there's any other legitimate locations to read e-books, and availability at libraries is probably limited for e-books. If you're looking for something else, well, go somewhere else.
There are tons of places where you can read Star Trek eBooks online for free. Barnes & Noble, Amazon, Google Play, the list is endless. It will, of course, cost you money to download them. But simply reading is always free.
I second https://www.hoopladigital.com/ it's a great service and it's 100% free and legal. There's a couple others out there like it, if your local library doesn't support Hoopla, ask your library if they do support something like it.
England has BorrowBox, but they've got a VERY limited selection. The only Trek on it is the first Prometheus book.
My library gives me access to both Hoopla and Overdrive. Their Hoopla account doesn't have a lot of novels, but it's got a ton of comics, including a whole bunch of IDW Trek. Overdrive has mainly novels, including a decent selection of Trek novels. My only problem with Overdrive for novel is you only get them for two weeks, and it takes me at least a month to get through an average length novel. Hoopla and Overdrive are both available on the Apple App Store and Google Play.
Archive.org has something called Open Library. Although the legality seems to be ambiguous. https://the-digital-reader.com/2018...hives-decade-old-open-library-decides-piracy/
Does your library's version of Overdrive allow you to renew the books? Mine does - it becomes available as an option in your borrowing list about 3 days before the book needs to be returned.
I'll have to check next time I borrow something. The only thing I've borrowed so far was the second Dresden Files short story anthology and I had already read all the stories that were up to where I was in the timeline, so I just let it end.