Generally speaking, tabs are not supported in HTML. If you’re attempting to format text by adding a tab at the start of a paragraph, you can either use spaces, or edit the stylesheet for your theme to add the
text-indent property to your paragraph elements.
If that’s beyond what you’re comfortable doing yourself, you might reach out to the folks at Codeable to have them knock out that simple edit for you: https://www.wp101.com/help/
Hope this helps!