Tos not showing up on the checkout page

I would like to have a Terms & Conditions check box on the MarketPress checkout page

A solution mentioned in this thread is no longer working:
https://premium.wpmudev.org/forums/topic/marketpress-checkout-screen-tc-check-box#post-1092731

The Tos is added at the page source, but it is o visible at the front-end and user can't procced because of the error

You need to agree with terms and conditions

Please advise how to make this code work.