What to do if the Xiaomi Truclean W30 Pro Wet Dry Vacuum cannot be charged?

If the Xiaomi Truclean W30 Pro Wet Dry Vacuum cannot be charged, please refer to the following information:
1. The self-cleaning charging dock is not connected to power. Correctly connect it to the power supply.
2. The vacuum is not placed properly. Correctly place the vacuum onto the self-cleaning charging dock, and make sure the vacuum is upright.
3. The charging contacts are dirty. Unplug the vacuum, and try again after cleaning the charging contacts.