Delay payment problem

Hello everyone,
I am trying to implement a process where user place the order first and wait for admin accepting the order. Then admin will send the payment email to the user. I hide the payment method, so user need not to choose any payment method.

But the problem is after user place the order, the download link suddenly appear. How can I fix it ? I want my user pay the money then they can download the digital product!

Thanks all!

Screenshot :

https://wordpress.org/plugins/woocommerce/