You can contact your provider through the Takl app. Go to the Current Chores tab, then tap the chore whose provider you want to contact.
You will be able to contact your provider at the following times:
Now Jobs: Once they have gone "En Route".
Scheduled Jobs: Within two hours of the scheduled appointment time.
This can be done by tapping the SMS or Phone icon on the job screen and will allow you to provide any further instructions or final details to your provider.