Add charts to visual report

I want to add a chart to a visual report but the button to add the chart disappears once the web page is fully loaded. Is this because I have a free account? If not, how can I make that happen?

Your Account subscription has nothing to do with how you create Charts on your Visual Report. 

It's possible, however, that the Chart from the Visual Report is not applicable for your form. 

For example, for this form only Grid is applicable: 

As for this form it is Chart and Grid

You can check these guides for your reference: 

How-to-Create-a-Visual-Report-with-your-Form-Submissions

How-To-Use-Visual-Report-Filters

I hope this helps. Let us know if you need any further assistance. Thank you.