edit: works now for some reason.
Alright, I just tried to invite a friend to the game after taking a break and I'm either blind or there's something broken.
Here's the site: https://playtogether.worldofwarships.eu/
There's no invite button, nothing to enter a email address or anything else. Yes, I'm logged in and service record 15. I tried 2 different browsers (Chrome and Edge) and ingame too.
Screenshots are attached.