On Steam you can do this by right-clicking on Apex Legends, go to “Properties”, “Local Files”, and then click on “Verify integrity of the game files”.

IF Apex Legends crashes on startup with error message Error reading pak file "common.rpak" Error 0x00000017, then see this post for the fix.

Fix Easy Anti-Cheat error that says Untrusted system file when launching Steam games like Apex Legends, Elden Ring, Lost Ark, New World, Jump Force, Watch Dog, etc.