First turn off the tap switch, find a blue spot under your hand, and open it with your hand, it will reveal a hole.
Look into the hole with a flashlight to see how the screws are held in place, then loosen them with a suitable screwdriver.
If the screw inside is the inner square hole will be more troublesome, to use other tools to remove.
After you unscrew this screw, you can remove the handle of the faucet, you can see the nut inside, you can remove it with a wrench, you can remove the spool.
Remove the bottom of the Xiaomi water purifier filter element, there are four MATS, remove the mat you can see four screws, remove the four screws can be removed.