I have successfully Magento 2.3 venia theme with my backend URL. And every query was validated and theme working successfully. But the issue is I could not add products in the cart. This 400 error is what I got.
POST /rest/V1/guest-carts/Hrx6ctErQTVBWkrTU6A8rlWyj4NfA1WN/items 400 3173.894 ms - 755
Also, product images return
GET /media/catalog/product/ 404 2875.405 ms - 7259
I couldn't even guess what is the issue, I need some react or Magento experts advice or help.