Working through the examples from Firebase Web App with ESP32 and ESP8266 ebook and came across the following compilation error in Streaming_Database_ESP32_Arduino_IDE.ino:
‘class FirebaseStream’ has no member named ‘to’
Same error with the Streaming_Database_ESP8266_Arduino_IDE.ino file.

Here is the code segment, last line is where the error occurs:

// Callback function that runs on database changes
void streamCallback(FirebaseStream data){
Serial.printf(“stream path, %s\nevent path, %s\ndata type, %s\nevent type, %s\n\n”,
data.streamPath().c_str(),
data.dataPath().c_str(),
data.dataType().c_str(),
data.eventType().c_str());
printResult(data); //see addons/RTDBHelper.h
Serial.println();

// Get the path that triggered the function
String streamPath = String(data.dataPath());

/* When it first runs, it is triggered on the root (/) path and returns a JSON with all key
and values of that path.So, we can get all values from the database and updated the GPIO
states, PWM, and message on OLED*/
if (data.dataTypeEnum() == fb_esp_rtdb_data_type_json){
FirebaseJson *json = data.to<FirebaseJson *>();

Typo?