Magento admin panel -> Sales -> PayPal -> Check "Payflow Link" and enter configuration options accordingly.
Then place a demo order. The 5th "Payment" step will say "Credit Card, you will enter your payment information later." Click Continue.
The 6th "Order Review" step should display order summary and a "Pay Now" button pops up below the order summary. I can toggle back to the magento default theme and the pay now button displays with no issue. With the hellomix template enabled, the pay now button never appears.
I have configured a second server with clean installs of both magento and hellomix and still have the same issue.