The Network Lerp Rigidbody classed as "Experimental" for now so please share any problems or bugs you find with it and use at your own risk if production builds.
The Network Lerp Rigidbody component synchronizes position and velocity of a rigidbody across the network. This component is useful when you have a non-kinematic rigidbody that have constant forces applied to them, like gravity, but also want to apply forces or change velocity to that rigidbody or server or client with authority. For example, objects that move and jump using rigidbody using gravity.
A game object with a Network Rigidbody component must also have a Network Identity component. When you add a Network Rigidbody component to a game object, Mirror also adds a Network Identity component on that game object if it does not already have one.
When using the Network Lerp Rigidbody you should NOT have NetworkTransform on the same object as the Network Lerp Rigidbody will handle syncing the position
By default, Network Lerp Rigidbody is server-authoritative unless you check the box for Client Authority. Client Authority applies to player objects as well as non-player objects that have been specifically assigned to a client, but only for this component. With this enabled, value changes are send from the client to the server.
Normally, changes are sent to all observers of the object this component is on. Setting Sync Mode to Owner Only makes the changes private between the server and the client owner of the object.
You can use the Sync Interval to specify how often it syncs (in seconds). This applies both to Client Authority and Server Authority.