To record the Non-Striker as the batsman dismissed, open the Wicket dialog as usual, click the Player Dismissed dropdown (which will default to the Striker), and select the Non-Striker. The Dismissal Type list will only display those by which a Non-Striker can be dismissed and will default to Run Out. If this is the required Dismissal Type, complete the rest of the Wicket dialog as usual and click OK, or select the appropriate type first and then complete the dismissal:
The Run Out Backing Up (Non Delivery) option will create a ‘delivery’ in the Ball by Ball panel, but not count it as one of the over as per the Laws, and will use the previous delivery for the Fall of Wicket. The Bowler will automatically be loaded as the Primary Fielder, as only they can affect this dismissal.