To add a Squarespace poll to your post/page:
1) Create a poll using the create a poll form
2) After the poll is created, locate the poll you created in the Dasboard
4) Chose a point where you want to your add your poll
5) In the pop-up window, select creating a new custom poll element
6) Paste the code you copied from “Script” tab
7) Refresh the page. The poll should appear.