You can use your preferred Message Template in a Sidekick Workflow. You’ll find all the available Templates under the “Message Template” option when you’re creating a new Workflow.
In case you’re not able to find it, make sure the “Object Type” is correctly chosen for the workflow and you have the intended message Template created in Sidekick’s Templates page.
We hope this was helpful! Please feel free to connect with our team if you need help or have any questions.