When you want to add a Substitute on a scoresheet.
On the scoresheet, Click on Options:
1. Click on Add Spare.
2. Choose the team to add Spare.
A spare button will appear at the bottom:
Click the Spare button.
3. Select the player you want to add as the substitute.
4. Click on Select games.
Choose the games that will belong to the spare/sub.
Click on Accept Spare!
If you need to add an additional spare, click on Options > Add Spare.
Then click on Spare and restart the steps from the beginning.