My baby fight his sleep so much

Kayley • 24 years old, I have a little boy who’s 4 and I’m TTC my second baby!! 👶🏻
Does any of your little one's like extremely fights there sleep, my son actual goes mental trying to stay awake, he shakes his head and moans so much for such a long time, eyes rolling in his head from being exhausted. What am i actual meant to do about this? It's so annoying it can go on for such a long time 😫