When working with SharePoint Online modern pages, you used to get only a limited number of options in the Text web part toolbar. To get the whole list of options, you had to open the Properties pane on the right side of the page. Now, you can access all the text properties from the toolbar. Here’s how that looks…
When you are editing text in a Text web part, you’ll see that the Text Toolbar now expands across the width of the web part, showing as many options as will fit:

If the web part isn’t wide enough, it’ll show an ellipsis at the end. If you click on the ellipsis, you’ll see a dropdown with the rest of the options:

If your web part is wide enough, you’ll see all the icons with no additional clicking to access all the options:
