I have installed “flameshot” and everything seemed to be fine.
But starting it, nothing happens at all.
Trying to reinstall it by bash, the info is “already the newest version”.
So, it´s installed but doesn´t work.
No idea why!
Have you fully updated your system and rebooted?
Does it give any information if you run it from a terminal e.g. konsole?
Were you able to get it to run?