Engagement instructions are exposed in the Presentation Mode and in the active poll view in the dashboard.
When you switch to the Presentation Mode, it will contain the instructions on what a person needs to do to access your online engagement or to vote with a text message.
Each of the options in your engagement is attached to a number starting from 1. To vote, your audience needs to send one of the numbers (as instructed in the Presentation Mode) to your dedicated phone number in a text message.