Wemos D1 R1 is an Arduino like board that has ESP8266 on board (specifically ESP-12F)
- File > Preferences > Additional Boards Manager URLSs: http://arduino.esp8266.com/stable/package_esp8266com_index.json
- Tools > Board > Boards Manager. Search for: wemos. esp 8266 by ESP8266 Community. Version 3.0.2. Install
- Tools > Board > LOLIN(WeMos) R1 D1