These are my app, gate and noise reduction filter settings, and the order they are enabled in for my microphone input. I am using the easyeffects flatpak which seems to include the standard noise reduction ML model.

You might need to study the gate settings for a minute to tweak them to your needs, I suspect you'll only need to change the curve threshold (-22db in my pic) to pick up your voice when you speak into it, but not background noises. You can use the db values shown in-app while speaking to help adjust it.