How to Mount freebsd-ufs USB Correctly to Transfer Files from One FreeBSD 12.1 computer to Another with 13.1

My Second Post. The First One Led to This Present One. I am moving from FreeBSD 12.1 on one computer to FreeBSD 13.1 on another computer. All of my desired files are placed in one directory. This is a simple job with nothing fancy; all that I want to do is copy one directory with subdirectories containing files onto the USB from the old system and then copy the same from the USB after I have created the new system. The procedure followed below was done on the FreeBSD-12.1-RELEASE version. I cannot do anything on the 13.1-RELEASE until I copy my files from the former because the former is what is being replaced by the latter. 1. I bought a PNY 256-GB 3.0 USB Backward-Compatible USB. 2. INITIALISATION. I attached the USB to the computer. /: cd dev /dev: gpart show // The new USB drive appears as da1. In the past, such drives have usually appeared as da0. /dev: gpart destroy -F dev/da0 /dev: gpart create -s mbr dev/da0 /dev: gpart create -s gpt da1 /dev: gpart add -t freebsd-ufs da1 // This command creates da1/p1. /dev: newfs -U /da1p1 // This takes several minutes to create cylinder blocks. // To verify. /dev: gpart show da1 // This reveals that the bulk of the USB is freebsd-ufs and a tiny part is reserved for adminitrative purposes, so to speak. // Just to be sure:- /dev: gpart show da1 // This gives the same information as /dev: gpart show da1. 2. MOUNTING. // To ascertain if this USB was mounted:- /dev: df // This USB did not appear, so I removed it from the computer, which let me know that the guest had departed. // I then attached the USB to the computer again, and it was recognised as an unmounted guest, so to speak. // Then:- /dev: cd / /: mount -t ufs dev/da1 media/USB // And the message spat back No such file dev/da1 /: mount -t freebsd-ufs dev/da1 media/USB // And the message spat back No such file dev/da1 // I then tried /: mount -t freebsd-ufs dev/da1p1 media/USB // And the message spat back No such file dev/da1p1 // I then tried /: mount -t ufs dev/da1p1 media/USB // And the message spat back No such file dev/da1p1 // Because ufs is the default, I then tried /: mount dev/da1 media/USB // And the message spat back No such file dev/da1 // I then made the final attempt /: mount dev/da1p1 media/USB // And the message spat back No such file dev/da1p1 3. SCREAMING. Having devoted the entire day to hunting for a solution, man ages, FreeBSD Handbook, this site, and other sites, I give up. I have never had this kind of trouble in ten years of mounting ufs USB's. Perhaps one of you kind souls will know what may be wrong.