I installed the text box app and the upload image app and neither are showing on the website. The developer reached out and could pull it up on their end but its not showing up on my end. I cleared the cache and still not working. How can I get these...

I added these two codes for a text box and upload files. They were added, but when I add a product to the cart I get this error message: Parameter Missing or Invalid: Required parameter missing or invalid: items. What do I need to add to the code or ...