Default Animations work but not Custom Animations Movement

Hello, I'm new to this and I've been having a problem with getting my model to move. I've been using an asset called "3rd Person Controller + Fly Mode" and when I substitute my model in, it works fine. However, when I try to change the animations to my own custom ones, the character does the animation in place. I've tested it out by switching out just the jumping animation to custom animation, where the character will run around but when it jumps, just jumps in place.

I have another PlayerScript that I made that allows the character to move using RigidBody.AddForce(velocity , ForceMode.VelocityChange) but it takes higher values and causes the model to slide about essentially and I have to manually add gravity. I'm essentially trying to figure out how to make the model move without having to specify a ForceMode.

Any ideas would be greatly appreciated. I could provide more information if need be. Thanks!