How to – Use the new command designer to customize the command bar – Dynamics 365 / Power Apps

Using the modern app designer either open an existing model-driven app or create a new model-driven app in https://make.powerapps.com/

Select Edit >> Edit in preview

Select any entity/table and select the Edit command bar (preview)

The different command bars that can be edited are the Main grid, main form, subgrid view, and the associated view.

• Main Grid view–

• Main Form view –
  

• Subgrid view–
  

• Associated view –
  

The legacy / classic button is not supported currently.

Check out all the known limitations

https://docs.microsoft.com/en-gb/powerapps/maker/model-driven-apps/command-designer-limitations

Let us try adding a new command/button in the Main Form, and see what options do we get there.

Select + New command or the + New option

It adds a new button with the label NewCommand with options to duplicate, hide, move up and down, etc.

The different properties that can be configured for the new command –

Let us Save and Publish

Click on Play and open a lead form.

We can see the new command added.

Get all the details here –

https://docs.microsoft.com/en-gb/powerapps/maker/model-driven-apps/command-designer-overview

Hope it helps..