Welcome to the forum. There are several ways but let's make sure you know some basics.

If you type three periods after a chord name, it causes that chord to Hold. Do this on the last chord of your song. Also make sure the song's length is long enough for the chord to decay. This could be the second number on that group of three, where the first is the Bar to repeat to, and the middle number is the ending measure of the song. For many (most?) songs you will use a Tag. In the Tag Settings (the icon marked S) you can select a four-bar ending.

That's a fast overview. Tell us what you've tried and what works or doesn't work. If I mentioned something you don't understand, write back, or use the Help menu.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.