Make sure you flash the tasmota32.factory.bin image Other than that, you can follow from step 7 of the Sonoff S31 smart plug mod tutorial
Arduino Setup Make sure to prepare arduino for programming the esp32
What is Tasmota and How to use it with ESP-01 to Control Smart Home Devices Home Assistant Tasmota Docs Tasmota Supported Devices Repository Tasmota Supported Modules https://blog.
Steps Pop off gray cover Slide out white slidy corner pieces