So you playing with a mouse against someone on the phone is kinda cheating but don't worry. Can mobile COD players play with console players? No.Only PlayStation, Xbox and PC players can cross play.
No you can't play with PS4 players because Call of Duty Mobile isn't on console. However you can play Call of Duty Mobile on PC with your mouse and keyboard, but on mobile you will play against PC players only if you play with friends that are playing on a PC. Can Call of Duty mobile be played with PS4 players?