Yes, you can download Windows 10 ISO to your iPhone and move it to PC using USB cable.
Sine you are using device (iPhone) that can't run Media Creation Tool you can download full ISO.
Go to linked page with browser on your iPhone, download ISO, transfer it to you PC. Once transfer is completed mount that ISO (double click or right click and select mount). That will create virtual CD/DVD-drive with Windows 10 installation files. Run setup.exe.
If your windows is older than v1909 then it will be updated or if it's v1909 then it will do in-place repair.