The Seen by provider is automatically populated in the Superbill based on what is recording in the encounter. The provider selected in the Seen by field of the chart note will also be listed as the Seen by provider at the bottom of the Superbill. The screen shot below illustrates where you can view which provider is assigned to a chart note.
This information is populated based on who is the Seen by provider in the schedule or it auto populates if the provider created a new encounter.
When you create a Superbill, the provider information will be listed at the bottom in Other details. Click Edit and change the Rendering Provider. Once completed click Add. This can be changed at any time prior to signing the encounter. Once the encounter is signed you may no longer change the Provider information.