recover deleted files

What’s happening?
Today I was configuring my gaming settings and I decided to delete a file from its folder.
Now the game doesn’t function properly.
How can I recover the file since its not in the trash bin?
Steam didn’t update and recover the lost file.
Can someone help me please?:’(

Generally, I restore them from my backups.

tempdecal.wad file was deleted.

Oh and custom.hpk file was deleted.
Anyone know how can I recover them?
I’m new to Linux.

It depends on what file system are you using and how you actually deleted the file (from Dolphin, command line, Thunar …) . If it is BTRFS than it might be easily doable using snapper (if this is still installed by default).
If you are using EXT4 you can try extundelete :

But keep in mind that you actually need to know what your doing so if you attempt that be sure to read the manual first. Otherwise you may loose all the other files on your partition as well.

To check what filesystem you are using you can use the first command in this guide :

If you delete from command line there is not trash bin. Deleting from a GUI should default go to trash but you can select hard delete and it is gone. If you have not written much to the file system since the hard delete then you may use some form of file recovery program. By default root is formatted BTRFS and home is XFS so different file systems depending on where the file is