Options for square with up arrow at bottom of screen

Thank you. I have tapped the triple dot icon before but cannot get MS Word to show up. There are apps listed with the green on button and others without that. Those just have the triple line on the right to move them up or down

Tap the arrow.

Scroll to the far right and tap the triple dots to add more items.

You can tap, hold and drag the items to the left or right to rearrange them.

The file type will determine which apps can be used.