Hey @shodan,
Welcome to the community!
I wouldn't give up on the phones you got just yet. After a quick bit of searching, I can't find any such phone as a Oneplus N10 Metro. I don't know much about these things, but could the device be locked to a cell carrier called Metro, and maybe that's coming up in the installer? In searching for a Oneplus N10 Metro, I noticed there's a cell company in the USA called Metro that seems to supply Oneplus N10. Sometimes a device is locked to a carrier, but often it is possible to unlock it. May be worth searching online for how to unlock the phone from Metro? But again, I'm really not sure this is the case.
Also, I see that you have Android 11 installed. In the device page for the OP N10, if you scroll down a ways, it states that you'll need to be using a specific version, Oxygen 10.5.7 or something. The system image or whatever you call it is conveniently linked from the device page. You'll need to download that file and install that version of android before installing Ubuntu Touch.
The other main thing you'll need to do , probably before downgrading, is unlock the bootloader. Search online for how. Takes a bit of doing, but it's all doable.
General installation instructions for Ubuntu Touch are found on the installer page.
Hope it turns out that your devices are what you thought they were, and useable for UT!