A little while ago I switched my late 2015 Macbook Air to Ubuntu (not dual boot) because I needed a linux computer for work. I overwrote the existing os because it was taking up a massive amount of the storage space and i said "I can always just use a bootable usb to switch back if i dont like Ubuntu". This might have been stupid, but it made sense at the time. There have been issues with Ubuntu and I like it less in general, and no longer need it for work, so I am trying to switch back to mac os. I tried booting the computer in Internet Recovery mode by holding Command + R and selected the Reinstall OSX option and went through the steps until I got to the part where you select the disk to install it on. Normally I think there would be an option called Macintosh HD there, but it is currently empty, as you can see in the attached image.
I also should mention that I have a bootable usb with High Sierra on it that I made with my other computer, and when I plug it in, and boot the computer while holding the option key and follow the necessary steps I get the same problem, where the hard drive is not visible, and only the bootable usb is shown. Is it possible that when I installed Ubuntu I overwrote the Macintosh HD? Is there any hope of getting back to mac os? Any help is appreciated.
Note: My Mac has a single internal SSD.