Hi,
Yes, it is possible to develop for the Raspberry Pi 4 using RT-Thread Studio, but there is an important limitation: the Raspberry Pi 4 BSP is not currently included in the default SDK Manager packages of RT-Thread Studio 2.1.5.
https://youtu.be/Gz9amRmX0DY
To use RT-Thread with the Raspberry Pi 4, you generally need to manually import the BSP from the RT-Thread source repository instead of installing it through the SDK Manager.
Ask How to download the Raspberry Pi 4 Board Support Package