How can I add a service to a group conversation?

On mobile devices:

In the conversation list:

1. Tap the name of the group you want to the add the service to.
2. Tap the group name at the top.
3. Toggle guests and services to on.
4. Tap  Add Participants.
5. Tap Services.
6. Select the service you want to add.
7. Tap Add.

A banner will appear at the top of the conversation stating: Services are active.