Permanent save file

No, once you inject it you don't need to reinject it anymore, it's permanent

what actually i can edit to be permanent? dlc? outfits? so forth and so on.

With a save file, you can increase the level and prestige of characters, amounts of items and addons, perks unlocked on a character (including unlocking a character's teachable perks), perk tiers, whether a character has legacy items (not recommended, high chance of a ban) and changing cosmetic loadouts, such as mixing a linked cosmetic with non-linked cosmetics.

I could've missed something in this list, but it doesn't matter. Cosmetic items cannot be permanently unlocked unless they are bought in the shop. Using Fiddler and a market file can temporarily unlock cosmetic items so long as Fiddler is running whilst Dead by Daylight is open, and the same can be done to unlock characters from DLCs. There are tutorials for doing such on this forum.

A save file cannot permanently unlock DLCs or outfits.

ah ok, so everything permanent, except cosmetics, thanks for the reply!

can you DM Me ?

Just to add to this thread: the "temporary" method is quite easy to use and doesn't require any repeated setup each time you play. Following LeViCodeR's 'gain everything' method, you only need to open Fiddler before starting DBD and that's it. I wouldn't shy away from the method because it's only "temporary", it's definitely a simple and long-term unlock after you've configured it once.