Hey! I have an acer ES1-132. They are practically same, just model no different. I think the problem here might be that while creating the usb using rufus, you might have selected mbr under partition scheme. Select gpt there and try again.
Also, when you are in boot settings and have a bootable usb inserted before getting to boot options, you will see something like “USB HDD : Toshiba…” instead of only “USB HDD”
I have a bootable lubuntu 19.04 usb created using same procedure. It’s a Kingston usb so for me the option is “USB HDD : Kingston DataTraveler 3.0”
Hope it helps. If not, then let us know. Here to help.