How to add paid app link in free app in iPhone?

I have developed two apps (Free and Paid) I will upload it on App store. But my question is how can I add a link in Free app to download Paid app. I would like to add a "Click to开发者_运维百科 buy full version" link.

Since I don't have any app on iTunes, so how can add a link on my Free app. And I have seen may free app doing this.

It's been a while since I did this so I may be mistaken, but don't you get an Application ID when you create a new app in iTunes Connect? In that case, all you need to do is create a new app but tell iTC that you're going to upload a binary later. You can use the App ID to create your link.

Upload the paid app first.
Wait untill it gets approved, and then you will have a link to it.
Upload the free app, with the link to the paid app