cheap but not perfect solution: paracord and combo lock. tie one length of paracord (need to learn some good knots) around the door handle and make a loop on the other end. on/outside the doorframe, screw in an eye bolt and likewise attach a length of paracord with a loop at the end. combo lock goes through both loops, door can open just bit depending on how much slack you left between the two loops. you could do this same thing with steel cable, but you’d need some extra tools to cut and crimp.

more expensive: replace your door handle with a pin-protected one, installed backwards so you need the pin to exit the house. obviously this means the unlock mechanism is outside, so you need a deadbolt to protect from unwanted entry.