i can't play 4:3 resolution on full screen

There is a solution. Add the following to the launch parameters: -windowed -w 1024 -h 768 + mat_letterbox_aspect_goal 0 + mat_letterbox_aspect_threshold 0 + building_cubemaps "1. Save and we open windowed mode. Press ALT + ENTER and the game unfolds without black bars in the game. In the field  -w -h enter your permission.

im familiar with this method thank you, but unfortunately its not good because when you alt tab from  the game it  goes to black bars again...
there was a time where you were able to write the mat_letterbox commands in launch options with no problem of alt tabbing from the game 

more then than that, i don't think that people need to mess around with this type of commands in the first place and creating autoexec files for this kind matter just for a resolution. why is it not available in the regular video settings like most FPS games... 
but thank you for trying to help though.

Remind me of a song of Sum 41 "Still Waiting"

need to sing it like this now: "So Am I Still Waiting for Apex to stop hating 4:3. Can't find a good reason to play native." Apex Devs fix this issue already!!!!