If the text is in a text box, table, or shape, first click the Text tab at the top of the sidebar, then click the Layout button.
Click the disclosure arrow next to Tabs, then enter the symbol in the Decimal Character box.
You can find currency and other symbols in the Characters window. To open it, choose Edit > Emoji & Symbols (from the Edit menu at the top of your screen).
To update the paragraph style with the change, click the Update button next to the paragraph style name at the top of the sidebar.
Any text that uses the paragraph style is updated with the symbol. If you aren’t using paragraph styles, or you want to keep the change as an override to a paragraph style, don’t click Update.