I get no valid data from DS18B20 connected to the OneWire bus (IO21). According to the schematic, there should be a pullup resistor.
I used the ds18b20.h from https://github.com/Xinyuan-LilyGO/LilyGo-HiGrow/tree/master/src.

Here is my application of TTGO T-Higrow Sensor (my post is in the German language - if required, use Google to translate)

https://ckarduino.wordpress.com/2021/11/16/messung-von-umgebungsbedingungen-fur-pflanzen-mit-lilygottgo-t-higrow-sensor/

There is no battery inside, but a loader circuit.
Must the battery be connected to VBAT pin? Which battery type is preferred?

Today I got the device and tried the Hellow World example.
I got the following compiler error:

Arduino: 1.8.15 (Windows 10), Board: "ESP32 Dev Module, Disabled, Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS), 240MHz (WiFi/BT), QIO, 80MHz, 4MB (32Mb), 921600, Core 1, Core 1, None"

D:\ArduinoSketches\LiLyGoMiniePaper_HW\LiLyGoMiniePaper_HW.ino: In function 'void setup()':

LiLyGoMiniePaper_HW:75:13: error: 'POWER_ENABLE' was not declared in this scope

 pinMode(POWER_ENABLE, OUTPUT);

         ^~~~~~~~~~~~

D:\ArduinoSketches\LiLyGoMiniePaper_HW\LiLyGoMiniePaper_HW.ino:75:13: note: suggested alternative: 'IBREAKENABLE'

 pinMode(POWER_ENABLE, OUTPUT);

         ^~~~~~~~~~~~

         IBREAKENABLE

exit status 1

'POWER_ENABLE' was not declared in this scope

I could not find the declaration of POWER_ENABLE anywhere.
Commenting on both instructions in setup() there are no compiler errors. But I get a cyclic reboot.

Why do I have to select ESP32 Dev Module and not ESP32 Pico?