How to update L1 certification for HiPad Pro?

The upgrade teaching video:

Here is the operating sequence:

Perform the following steps:
Step 1: Turn on the tablet, connect WiFi, then click the “Wireless Update” app.
Step 2: Click the " Check for update" button.
Step 3: Click ‘download’.
Step 4: Choose ‘Factory data reset’.
( a: Click the volume button’+'and ‘-’ to make option; b: click the power button to confirm selection;
c: the tablet will reboot automatically after factory data reset, then the device will work normally after OTA update again)