hi all!
A very convenient cheap programmer for STC. In fact, it is a regular USB converter, but with a function of short-term power supply shutdown of the circuit and chip to activate the bootloader built into the chip.

Аvailable at any of the links.
https://www.aliexpress.com/item/4000027276498.html
https://www.aliexpress.com/item/1005004606266866.html
https://www.aliexpress.com/item/1005005499576966.html