Can't install on 2018 MacBook

[RachelThorn]

I am trying to install elementaryos-8.1-stable-amd64.20260107.iso on a 2018 12-inch MacBook, model #A1534, but the installation always stops at the "select drive" step and there is no way to proceed. I am using a 4TB USB SSD as a boot/install disk. At first I wanted to make a dual boot system, leaving a small partition for Mac OS Mojave (the newest OS that works with this machine), but at this point I'll be happy to get elementary OS installed in any form, with or without dual boot.
Regardless if I choose "Erase Disk and Install" or "Custom Install (Advanced), no disk or partition appears for me to choose. I can open GParted, and it shows the current status of the disk, and allows me to make changes, but after I apply changes, no disk/partition appears for me to select. As you can see from the screen shots, I made a 512MB fat32 partition, an 8GB linux swap partition, and with the rest of the disk space I made an ext4 root partition. This is all the more frustrating, because I made a donation when downloading, never thinking I might not be able to install at all.
I also tried typing "e" for "options" on boot, but 1) the type was so tiny on this 12-inch screen that I (not joking) needed a magnifying glass to read it, and 2) I couldn't see anything on that screen that would allow me to install. I didn't try "c" for command-line interface, because I have no idea how to use the CLI to install, and have not been able to find instructions online.
Any help would be very much appreciated.