My 2015 MacBook Pro 13's internal SSD died during an update yesterday. When I try booting it says there are no drives to boot from. I used Internet Recovery and there is no sign of the internal SSD anywhere.
So, I plugged in a brand new 1 TB external SSD, it installed El Capitan and it worked perfectly. I updated it to Sierra without issues but when I try to update it further to High Sierra and beyond I get a message saying the disk doesn't have a firmware partition. I google this issue and it seems that MacOS versions released after Sierra require a working internal storage disk in order to install. Is it possible install the High Sierra in a USB stick and use that to run the installer?
Edit: It was running Mojave when it died, I had noticed that it was running much slower than usual which is why I tried updating it.
I was also wondering if it is possible to install Windows 10 in a different partition of the same external SSD since the stuff I need for work runs on it, however I can't get bootcamp to work without a internal SSD either.