getting RSYNC (or GRSYNC) to work right over my SSH on my internal house network

Guys, I have several computers at my house. I have one router in my livingroom which is directly connected to my cable modem. This livingroom router has 4 ports- one of which is wired into my basement, and it goes outside of my house about 75 feet to my shop underground. Inside of my shop the other end is connected to a network access point I bought so I could have wifi in my pole-building shop. It is a metal building- so I don't get any wifi from the house (no signals go through the metal building walls). That being said I like to listen to my MP3s in my shop when I am working and I have an old laptop that I run debian 9 on which I keep in there. Mostly I just use it for MP3s and youtube. In my house, my daily driver PC (which has linux mint 20) has about 5000 mp3's on it. I want to manually run GRSYNC, or RSYNC to make an identical copy of my mp3 folder on my shop laptop which I can always sync to my daily-driver computer.

My experience with GRSYNC has always been with copying a folder to my USB stick. Today I tried to get this to work where I could GRSYNC over SSH. I was able to sit in my living room and "connect to server" to the computer in the garage which I am pretty sure is SFTP. I put in my shop computers local IP 192.168.1.19 port 22, and then I could copy files to the folders I wanted to. However, when I tried to understand what syntax of "source and destination" in GRSYNC to get this to work I totally failed.

do any of you use rsync over SSH like this?