Restore without a computer
On vacation with no computer. Got the restore error on my sons iPhone.
Question marked as
Restore requires a computer......PC or Mac.
If the Restore screen appears on your iPhone, iPad, or iPod touch - Apple Support
If near a hotel, you might be able to use the computer in the lobby. If near a Best Buy, you could use a Mac there.
If near an authorized service shop, they can help as well. See document below for locations: