Help with using blender animations

Hello,

I am creating a first person system, and finally decided to use blender for my animations. But I am having problems with it.

I used this tutorial : Roblox Animations In Blender | TUTORIAL (2.80) - YouTube

I rigged my viewmodel, and gun and put it into blender. Then I animated it, and imported it into roblox. BUT however, the animation would not show up and I cannot figure out why. Could it be because I’m using blender wrong? I can’t figure out.

Anything helps.