FireBeetle Covers-ePaper Black&White Display - Character display

I have a question.
I use FireBeetle Covers-ePaper Black&White Display with FireBeetleESP32.
However, characters can not be displayed.
I used the following sample code.
https://github.com/DFRobot/DFRobot_ePap ... trDemo.ino
In the following sample code, graphics are displayed but characters can not be displayed.
https://github.com/DFRobot/DFRobot_ePap ... reDemo.ino

Please kindly advise.
I use FireBeetle Covers-ePaper Black&White Display with FireBeetleESP32.
However, characters can not be displayed.
I used the following sample code.
https://github.com/DFRobot/DFRobot_ePap ... trDemo.ino
In the following sample code, graphics are displayed but characters can not be displayed.
https://github.com/DFRobot/DFRobot_ePap ... reDemo.ino

Please kindly advise.
