How to send data from firebase php to arduino?
add global variable String data; and in loop()

data = "trash=";
data += Trash;
data += "&amp;distance=";
data += distance;
data += "&amp;temp_f=";
data += temp_f;
data += "&amp;humidity=";
data += humidity;

// build HTTP request
getStr = "POST /upload.php HTTP/1.1\r\n";
getStr += "Content-type: application/x-www-form-urlencoded\r\n";
getStr += "Content-length: ";
getStr += data.length();
getStr += "\r\nHost: gg.com\r\n\r\n";
getStr += data;