You'll need to use a computer to back up your iPhone to iTunes or Finder, but you can use as much storage space as you have free on your computer.
Apple removed iTunes from macOS 10.15, with its backup functionality now available directly in Finder. Therefore, if you have a Mac running macOS 10.15 or later, you should use Finder to back up your iPhone, while if you have a Windows PC or a Mac running an earlier version of macOS, use the most up to date version of iTunes.
Step 1 Click the Back Up Now button in iTunes or Finder. Wait until the backup is finished, and don't disconnect the USB cable until then.
Step 2 Ensure This PC or This Computer is the backup location, not iCloud.
Step 3 Click the Back Up Now button in iTunes or Finder. Wait until the backup is finished, and don't disconnect the USB cable until then.
Step 1 Connect your iPhone or iPad to the computer with a USB and open the iPhone section on iTunes or Finder.
Step 2 Tick Sync with this iPhone over Wi-Fi, then hit Done at the bottom of the window.
Step 3 Disconnect the USB cable from the iPhone. At the same time, ensure your iPhone is on the same Wi-Fi network as the computer. If so, the iPhone pane should still be available in iTunes or Finder.
Step 4 Click the Back Up Now button in iTunes or Finder, and a backup should be taken over Wi-Fi.
Aispyer IS DESIGNED FOR LEGAL USE ONLY. It is a smartphone and tablet monitoring software that shall be used only with the aim of parental control of their children, by employers to monitor the devices which belong to them and on which the employee’s work, on a device which is of your ownership, and by you with a consent of a device owner.
Failure to do so is likely to result in violation of applicable law that could result in severe monetary and criminal penalties imposed on the violator. You should consult your own legal advisor with respect to legality of using the application in the manner you intend to use it prior to registering, downloading, installing, and using it. Aispyer cannot be held responsible if a user chooses to monitor a device the user does not have the right to monitor; nor can Aispyer provide legal advice regarding the use of the software.