Amazon.com: Stemedu 2PCS USB to ESP8266 Adapter Module ESP-01 Prog ESP-01S Programmer Downloader CH340C Driver with Reset Button, Easy to use : Electronics
USB to ESP-01 Adapter Board Modification : 3 Steps (with Pictures) - Instructables
ESP8266 Programmer with USB-Serial Adapter - V3.0 from BurgessWorld Custom Electronics on Tindie
uart - ESP8266 Programming using ESP-01 to USB converter - Arduino Stack Exchange