So i've been following this tutorial
https://www.youtube.com/watch?v=CrqhqfGgMGk&t=0s , which is from 2014, so he's not importing an fbx file, but since now we only have to work with fbx files i'm having trouble following along, because when i import the hero file and add a skin modifier to my weapon model, i can't pick the bone im supposed to since its not displaying in the add menu, only the models that i imported, which are not bones.
I made sure to check the fbx files options and i made it so that it doesn't import the bones as dummies but the problem persists.