Unable to boot to a removeable device on a MacBook Pro running Windows

I'm trying to boot from a removable installation media on a 2019 MacBook Pro running Windows 10 (I installed Windows using bootcamp but I've since deleted all MacOS volumes, including the recovery ones)

I'm attempting to boot to a 8GB Ubuntu installation USB, I'm going to dualboot it alongside my existing Windows installation. When I enter the boot selector during startup, the USB drive shows up as "EFI Boot", when I attempt to boot into it, I'm redirected to internet recovery.

I've tried multiple times to start internet recovery, but it returns an error when it's completed. (I've been using my phone's hotspot for this)

When I was searching for answers on how I may be able to boot to my removable device, I heard that the T2 security chip prevents booting to external media. the solution for this seemed to be that I need to enter MacOS Recovery (using Command + R) and somehow enable booting for external media, though I'm unable to do this as I've removed the recovery volume(s).

I've also tried creating APFS volumes using a third-party windows utility hoping that this may allow internet recovery to do whatever it needs to do (but this didn't seem to work).

And I've tried booting to the device using the Windows BCD menu, but the only option to boot to is "MacOS X", which has been removed from my device for around a month or two now. when I attempt to boot to it, it boots to Windows instead. I checked the EFI partition using Powershell and it seems that there are 4 directories; APPLE, Boot, Microsoft, and refind.

(I've also been unable to boot into refind, though I don't really care about it anymore.)

I've also tried using WSL (Windows Subsystem for Linux) as an alternative for this, but I've been unable to use that for what I need to do. If I can't get it to work, I have a desktop already dualbooting Windows and Ubuntu, but I'd prefer to have it on my laptop too for whenever I'm moving around.