How to provide input from jupyter notebook to custom overlay's vhdl module and output the digital waveform to arduino digital io pin on PYNQ Z2?

I am trying to create an overlay for controlling my WS2812b led strip. The vhdl module has input(clk, no_of_leds, color_hex) and output (dout). How do I pass “no_of_leds” and “color_hex” values from notebook to overlay? and how do I interface the “dout” to external io port? (In logictools pattern generator we can define the pin to which we can direct the waveform to. I am looking for implementing something like that for “dout”)
Just Asking: Is it possible to input the pin name in a C function and output waveform to that pin from the function?
PS: I am a beginner, any and all inputs are welcome, Thank you.