Arduino for STM32

I've built a DIY keyboard with the stm32f401 black pill. It works, however the only 1 thing that is bothering me is that I cannot get the caps lock state. So whenever i connect a different keyboard and press caps lock, then I have no way of knowing the current state (I need to know because I have a led on the capslock, which I need to light up when the other keyboard presses caps lock.) Is there a way for receiving a signal when the caps lock state changes? Im using PlatformIO with the standard keyboard library from stm32core https://github.com/stm32duino/Arduino_C ... yboard/src