This is the well-known problem of Teensy, and you forgot to follow the instructions in Packages’ Patches for Teensy as follows:
2. For Teensy boards
To be able to compile and run on Teensy boards, you have to copy the files in Packages_Patches for Teensy directory into Teensy hardware directory (./arduino-1.8.13/hardware/teensy/avr/boards.txt).
Supposing the Arduino version is 1.8.13. These files must be copied into the directory:
./arduino-1.8.13/hardware/teensy/avr/boards.txt./arduino-1.8.13/hardware/teensy/avr/cores/teensy/Stream.h./arduino-1.8.13/hardware/teensy/avr/cores/teensy3/Stream.h./arduino-1.8.13/hardware/teensy/avr/cores/teensy4/Stream.h
Whenever a new version is installed, remember to copy this file into the new version directory. For example, new version is x.yy.zz
These files must be copied into the directory:
./arduino-x.yy.zz/hardware/teensy/avr/boards.txt./arduino-x.yy.zz/hardware/teensy/avr/cores/teensy/Stream.h./arduino-x.yy.zz/hardware/teensy/avr/cores/teensy3/Stream.h./arduino-x.yy.zz/hardware/teensy/avr/cores/teensy4/Stream.h