When you first add your site to the account, you will receive the code to implement, and you can copy it, send to your developer, or ignore until you're ready to implement.
At any point after that you can find the code in the Website Settings.
From the Website Dashboard, go to the Website Settings:
There, you will find the code:
Click on "Send by Email" to send the code directly to your developers for implementation.
Once the code is implemented on the site, the "Not Connected" message will be replaced by a "Site Connected" message.
* Note - the code is unique per domain. If you have accounts for multiple websites, or websites with sub-domains, make sure to implement the correct code for each domain.