In the Arduino ESP8266 Web Server library, you can use the arg method to get the value of a specific query parameter. Here’s an example of how you can do this:

server.on("/getValues", HTTP_GET, []() {
    if(server.hasArg("myParam")) {
        String paramValue = server.arg("myParam");
        // Use paramValue...
    server.send(200, "text/plain", "OK");

In this example, server.hasArg("myParam") checks if the request contains a query parameter named “myParam”. If it does, server.arg("myParam") gets the value of the “myParam” query parameter. Replace “myParam” with the name of the query parameter you want to read.