Cellular update on iPhone 11plus failed. I haven’t a computer to back it up on
Cellular update failed on my iPhone 11 plus. I don’t have access to a computer either.
iPhone 11 Pro Max, iOS 14
Then you do without. Or you purchase a replacement iPad. Or find somebody else with a computer. Or you schedule a Genius Bar appointment, or an appointment with another repair provider. Or you ship the iPad to Apple or another repair provider.