A better way to use ESP-01 as WiFi shield – E-Tinkers
Ch340 Usb To Esp8266 Esp-01 Esp-01s Adapter 4.5v-5.5v Wifi Converter Programmer Module For Arduino Smart Home Wireless Control - Integrated Circuits - AliExpress
Flash Firmware on ESP8266 (ESP-01) using Arduino MKR - Hackster.io
Usb To Esp8266 Esp-01 Esp-01s Wifi Adapter Module Ch340 Usb To Esp01 Esp01s Ttl Driver Serial Wireless Wifi Module For Arduino - Connectors - AliExpress
How to configure Arduino IDE and program ESP-01 with USB To ESP8266 01 Serial Adapter - YouTube