I cannot program the HT-CT62 through the serial port

I raised IO2 and IO8, lowered IO9, and raised EN on the HT-CT62 according to the ESP32-C3 manual, but I couldn’t program it normally. What is causing this? Does this module require any special settings for programming? I measured that for a normal ESP32-C3-WROOM module, the serial BOOT is low, but for this one it is high. Is this why it cannot be programmed? How can it be programmed, then?