According to the Forum Help section, you need to enable polls in order to use them:

How do I put a poll in my post?

Putting a poll in your post is simple.

If polls are enabled, start by creating a new post in a forum. Below the body of your post, you will see a text box that allows you to specify how many polls you want to have in your post and the system will guide you through the rest.

I cannot see a text box under the body of my posts that allows me to create polls. I cannot find a function that allows me to enable/disable polls either.

How can polls be enabled?

Can you add a button for enabling/disabling polls to every thread or to the Edit Profile section?