Do you have "Text to Speech" enabled under your Apex Legends game settings? If so, try disabling that.
Do you have boost mode enable don your PS4 to see if that helps get around this error and how full is your hard drive? I'm concerned the game is putting the system over the tipping point of where the hardware is struggling to run the game. Is the system dust free and well ventilated?Here is PlayStation's article on what to do when you receive that specific error code: https://www.playstation.com/en-nz/get-help/help-library/error-codes/ce-34878-0/
Hope this helps, keep us updated. 
