If you'd like to make any adjustments to the ETA text that's sent by dispatch when technicians are on the way, you will need to head to the Integrations page from the Manage dropdown menu.
From here, click on the Connect button located under the PowerMagic field service integration.
Click on the pencil edit icon next to the location you'd like to adjust the message for.
Once you've arrived to this page, you'll notice the Job Events dropdown windows. From here you'll want to select the Dispatched menu. Click this and a text box will drop down for you to type a new message.
Type up the message you'd like to send to your customers, hit the Update button, and you'll be all set!