This ESP-01 Firmware from AI-Thinker support AT Command on ESP-01 and ESP-01S Module.
STEP 1: Connect ESP-01 or ESP-01S Module to Laptop in Programming Mode (Short G0 Pin and GND Pin)
STEP 2: Use ESP8266 Flasher to flash latest firmware in ESP-01/ESP-01S Module
STEP 3: RESET ESP-01 Module before testing AT Commands (Short RST with GND Pin)
STEP 4: Use Serial terminal program like CoolTerm and Test AT Commands
Download CoolTerm: https://download.cnet.com/CoolTerm/3000-2094_4-10915882.html