Need help making a connection between a object and a object

I need help making a connection between a object and a another object using the physics joint, but it says I do not have any objects to attach it to, yet I have two other objects.

Screenshot 2025-01-04 3.48.56 PM

Screenshot 2025-01-04 3.49.10 PM

To use Joints, the object you want to attach need to be solid and movable.
If you want to connect an object without a hitbox, you can do that with an attacher.