Payments processing but cart is not secure

Site URL: http://carol-colin.squarespace.com/orangessardines-press

My store is set up connected to Stripe to accept credit cards. Purchases have been made. But, my cart is not secure. I think I need to insert live API keys someplace. How do I do this??? I have copied and saved them. 

Incidentally, the Squarespace 'contact us' to email for help is broken, as far as I can see online. The page loads as a long column of black on white text, and clicking 'contact us' just brings me back to the top. I have already emailed with Stripe and they said Squarespace has to help me set up the API keys.

Please help me.