The below Microsoft article will have a section called "Choosing ringtones" that can referenced.
https://support.microsoft.com/en-us/office/manage-your-call-settings-in-teams-456cb611-3477-496f-b31a-6ab752a7595f#:~:text=Change%20your%20default%20mic%2C%20speaker,Teams%20to%20use%20by%20default