That claim - widely reported over the last decade as an anti-green talking point - is at best misleading. Although there have apparently been lots of new coal plants approved:
1. A lot of them aren't actually built: someone did an on-the-ground check a few years ago and found quite a few empty development sites. So, "approved" doesn't mean built;
2. The ones that are built don't operate at capacity;
3. The ones that are built aren't in the slightest bit financially viable;
4. There's more coal plants but despite that China is actually burning less coal;
5. Relevantly, it's the regions that are approving new coal plants, not the central government.
One of the ongoing tensions in China, dating back probably thousands of years, is that between the regions and the central government.  The short answer is that the central Chinese government is pushing decarbonisation, solar, batteries and EVs and the regional governments are approving coal plants.  Which if they're actually built probably aren't operating and if they are operating it's not all the time and most likely at a loss.
China puts coal on back burner as renewables soar ? Centre for Research on Energy and Clean Air
China is building more coal plants but might burn less coal
China Allows New Coal Plants, but With More Limited Role - Yale E360