Just through WiFi, the lamp's master is ESP8266, which is a very widely used WiFi SOC lamp that has not yet been configured, will create an open hotspot by itself, and the mobile phone can communicate directly with the lamp through WiFi after connecting to the hotspot.
Then through the input on the mobile phone, the SSID and password of the router in the home tell the lamp.
Then the lamp is connected to the router in the home and closes the hot spot just created by yourself, and then it communicates with the mobile APP through the router in the home.