The Song Database (SDB) is a program to show lyrics on a digital projector for worship in a congregation. It is available for free for all major platforms, see https://zephyrsoft.org/sdb for more information.
This app can display the data produced and managed by Song Database if the file is accessible via a URL (web address). This app cannot be used for anything else, so if you don't use Song Database, this probably isn't for you!
If you don't want to upload the file containing the songs every time you modify it, you could set up a synchronisation solution like Nextcloud (see https://nextcloud.com for more information) and use the "share link" functionality - the resulting link has to be used in the app.