As of December 2025, OBS does not have native MIDI control. The most popular option is the obs-midi-mg plugin. But maintenance has stalled and I was not able to make it work on latest OBS versions ...

Install Python with version >= 3.9, or conda create a virtual environment of python version >= 3.9 Click Menu Tools(工具)-->Scripts(脚本), you can see a new window, click Python Settings(Python设置) tab, ...