My animated entity won't play animations

good afternoon, i'm trying to make a boss in minecraft with geckolib plugin, but when i test it i spawn the boss and he doesn't play animations (for example the walking animation). i also tried to make a procedure to make the triggers for animations, but i don't find "setup class (geckolib)". can someone help me? im using mcreator 2023.2 and geckolib 2023.2