Change static library project target device in STM32CubeIDE

I'm creating a static library project that is portable across many mcu because it is target indipendent code. The problem is that once I created the project, it seems impossible to change che mcu setting inside Project Properties > C/C++ Build > Settings > Tool Settings panel, as shown below:

The box is grey and the compilation flag -mcpu is fixed and cannot be changed.

I wanted to make different build configurations with different target devices.

Is there a way to do that?

Thank you for your time.