Read 433Mhz remote's code

Hi there!

I'm trying to duplicate my garage's gate's remote in a standalone board that I need to mount on my bike, so I don't have to look for the right button in my pocket everytime.
I have a couple of TX RX 433Mhz modules, and I need to reproduce the code.
I know it doesn't use rolling code.
I was told I need to use a logic analyzer to read the code, but not how to use it.

Can you please describe me how I should use the logic analyzer in order to get the code, and how to reproduce it through the TX module, please?

Thank you guys, you're awesome! =)