What plugins do you have? Updating OBS from v27 or earlier to v28 or later will break most of them, so you'll have to update them too, which is a separate manual step for each one. If you open the new version of OBS with the old versions of the plugins, you'll probably lose all of their settings because OBS doesn't load the old plugins, and thus their settings, and then it overwrites the saved settings (like it does normally) with what it did load.
So if you're going to do this, BACKUP EVERYTHING FIRST! If there's no export or backup button, make your own copy. Screenshot, notepad, whatever, but make sure you have it before you update!
Anyway, how did you get OBS in the first place?:
- PPA (see below)
- Snap
- Flatpak
- Build from Source
- Etc.
It could be that your particular source hasn't updated yet, and so you can't update yourself from there either.
The last sticky in the Linux Support forum is this:
The Linux version of OBS is still under development and contains many bugs, but if you're feeling brave, and can install Ubuntu PPAs, then you can give this a try. If you're on Ubuntu 14.04 LTS, you'll first need to install FFmpeg: sudo apt-add-repository ppa:kirillshkrogalev/ffmpeg-next sudo...
obsproject.com
It's for Ubuntu, which is
based on Debian but still has some differences, while you have Debian itself, but maybe it still works?
On Ubuntu, if you have the native package (not snap or flatpak), you can just do that, and then the normal
sudo apt update && sudo apt upgrade
will get you the new version. I use the PPA, and it just updated to v29, by the way.