If your apartment is over a crawl space it’s pretty easy to go down , over and up. You can just drill a hole in the bottom of the sink cabinet and floor underneath with a real long bit, and one through the floor behind the fridge. I used flexible plastic line, it’s easiest because of no elbows or connectors just the ends. If you have no crawl space but an attic you can go up and over but it can be hard to go up and down through the wall cavities, you’ll need a snake and you need to drill through the wood at the top of the wall cavities. If you have neither you’ll have to get creative.