Invalid Stripe Token

I want to being by saying I’m far from a coding expert.

I downloaded, installed and activated the plugin, and watched the Setup and Shortcode Usage Video to better understand how to get the payment button to appear on my site (www.nextgenerationwatersummit . com / exhibitors). I was able to follow along and get the button to appear, but when I click on it, I do not get a popup window as the video shows. Instead, the checkout result page loads and I get the following error message:

Invalid Stripe Token

I do not know what that means, nor how to fix the shortcode to have the button function properly. I look forward to any assistance the community can provide, and I will answer any questions in case I didn’t describe my situation thoroughly. Thank you.