The first step is to create your eBay Partner Network account, if you do not already have one.
You can create your account here.
Once your account is created and you are logged in, click on Campaigns and create a new campaign
Fill in the necessary info about your website and then grab your Campaign ID:
Next, you will need to create an App ID. The first step is to create an eBay Developers account.
You can create your account here
It will usually take about 24 hours for your account to be approved. Once you are approved you can login to your account.
After you login you can enter in an Application Name, it can be anything you would like.
After you enter in a name, you can then click on Create A Keyset:
Fill in the required info and create you IDs.
You will want to grab your App ID and insert it into the software under Settings: