Hello, my child has a cough. When he coughs, I see that mucus comes ou…

Hello, my child has a cough. When he coughs, I see that mucus comes out (almost), but he swallows it back. The child is one year old. How to remove the phlegm? I do inhalation for him, and I smear him with Interfer Maza. I clap on his back like a drainage massage (I saw on YouTube). But he doesn't want me to do this, maybe it will cause a masseuse ? I saw how masseuses remove the phlegm through massage.