In our example, we display three input fields and each field has a “Submit” button. When the user enters data and presses the “Submit” button, that value is sent to the ESP and updates the variable.

Setting/Resetting input/output ports using website buttons under ESP8266/ESP32's AP mode. - youjunl/http-server-on-Arduino ...

Arduino has a library for quickly and easily setting up a simple web server on an ESP8622-based board, and [Tomaž] found that power consumption on an ESP-01 can be reduced a considerable amount ...