How to skip selecting party member if your game is only using a single character for battle?

Version 3.0.45

As the title states. If I'm making a game project only using a single character that will fight and be controlled. How do I get rid of the step or action to make you select the person every time you need to take an action in battle?

Not possible yet without a plugin, but I can make it a core feature, does not make sense to have this step with a single ally.