Buying overseas is not always a crap shoot but you have to read the specifications carefully. I retrofitted my home with LED fixtures ordered from China and to date have no complaints but I learned early that the default voltage worldwide is 220V. Check the listing at the Fastech website because some of their heaters specify 220V but are listed as having a “two pin flat plug” which would obviously be a US plug but usable only on 220V. It’s possible you ordered one with a US plug but 220V.
https://www.fasttech.com/products/0/10057570/9675020-400w-portable-touch-control-smart-electric-heater![](https://i.postimg.cc/g2tm8y3z/heater.jpg)