Use three simple steps to play your own file:
If you are happy with the way Coria allows you to practice this song, you can make it available for others. Download it in HTML format and distribute it via email. When the recipient opens the file (for example by double clicking it) the piece will be shown in Coria.
You can also publish the file on a website, for example the website of your choir. The details depend on the setup of the website.
If you plan to distribute a piece it is useful to enter the information about the the piece (title, names of the parts) as much as possible.