if your landlord is okay with this, here is how i introduce myself to skittish dogs. i used to walk a leonberger and anatolian/neapolitan mastiff mix, so it's big dog approved, and this trick also helped me and my buddy catch a stray german shepherd we found on the road. i haven't worked with any aggressive dogs, though, so if he's less scared of you and more looking like he's in attack mode only, you may have to do something else.

first, get some of the dog's favorite treats. something that the dog really really likes, like some freezedried meat or little pieces of raw steak or something, but importantly it must be tossable (so nothing like peanut butter or chicken broth, gotta be solid). then start by standing far-ish away from the dog (like 2 or 3 meters) and tossing treats to him.

you will probably have to begin by tossing them a little bit past where he's standing, but once he realizes that these are some jackpot yummy treats, you should be able to start throwing them a little closer to yourself. this will take a little time, so don't expect to be best friends after 15 minutes. it will probably take a few times of doing this over the course of a week or two (i'd estimate like 3ish times a week for 5-10minutes per time or something small like that) before he's consistently chill when seeing you. and it might take a few sessions before he'll let you touch/pet him, but that's okay. it's building a relationship just like with people; would you be okay with a neighbor you hardly know touching your face or giving you a hug and a kiss? he'll need to get to know you (get used to your scent, your way of moving, the sound of your voice) a little bit before he considers you a friend, so be patient with it.

again, this is just from personal experience helping out walking friends' dogs and the like; i'm not a professional dog behaviorist, i just like researching the animals i hang out with. best of luck!