Need advice on crate training and restless puppy

Hello guys, I need some advice on how to crate training my puppy so he finds it a safe place. We have a 15week old rottweiler and I have noticed that he doesn’t rest properly and avoids his crate (I didn’t force him to be there but rather make it his choice to be in there).. Whenever I am in bathroom, working from home or leaving him for shop runs, he sleeps somewhere near with always being in alert mode. When I get up, go somewhere he follows me. I have given him kong to his crate, however, when he is done with it, he just leaves the crate and goes to nap somewhere close to me. Also, when I leave him for shop runs, I leave a Kong in his crate, as soon as I leave he goes on to lay near the door (and sleep?, my camera doesn’t cover his exact laying spot)…

I need some advice on how to manage this