It's still in theatres in Japan. It had a limited run in Korea a couple of weeks back but that might be over now. Otherwise, we just have to wait for it to be released digitally and physically, which can take a few months.
How to watch with subs though? I did try joining the discord but still no updates
The soft subs are on the website itself. However, I did read that due to a bot problem, the site is not open for registration at the moment. You may want to check out the comment below that may have it in a different discord.
The screenwriter Ueda Makoto really likes playing with time. The more I think of this movie, the more I feel like I need to map it out more. It really is an interesting take, though!
There's a heck of a lot of plot here. Similar to how Konomoto wrote Odd Taxi, there are various details that are there and rewarding once mentioned again. The last few episodes are really good when things start to come together, but I still think the series was a bit too long to get there.
https://x.com/kaede_movie1219/status/2042409588549697874
https://www.vap.co.jp/stmoon-movie/