You can assign a shortcut key (F1—F8) to a paragraph, character, or list style, and then use the shortcut keys on your keyboard to apply a style to your text.
Note: To use shortcut keys on a portable computer, press Fn with the shortcut key.
Click any text in the document.
Click the paragraph style name at the top of the sidebar on the right.
If the text is in a text box, table, or shape, click the Text tab at the top of the sidebar to see paragraph styles.
Do one of the following:
For a paragraph style: Click the paragraph style name at the top of the sidebar.
For a character style: Click the Character Styles pop-up menu.

For a list style: Click the Bullets & Lists pop-up menu.

In the pop-up menu, move the pointer over the name of the style you want to assign a shortcut to, then click the arrow that appears.
Choose Shortcut, then choose a key.
Now, the shortcut key appears next to the style name in the menu for easy reference.
To remove a shortcut key assignment, follow the steps above, then choose None from the Shortcut menu.