If you are on at least WooCommerce 3.4 Version you need to set your privacy settings page within WooCommerce Settings > Accounts & Privacy > Privacy Page.
Below WooCommerce Version 3.4 Version?
If the privacy policy Acceptance Checkbox does not show you need to make sure, that you have set a terms and conditions page within WooCommerce Settings > Advanced.
I have do this that you tell in WooCommerce Settings > Accounts & Privacy > Privacy Page., but we haven’t check box!!
Still don’t have a checkbox 🙁