Creating a Twitter Ads API account is nearly identical to creating the Basic Twitter data connection with a couple of extra steps.
First for the instructions in this guide for creating the Twitter App
Once you have the app created and an app ID, go to the URL below to fill out the Ads API Application form.
To gain access to the Ads data requires approval from Twitter.
Once the form is submitted you should receive a response back within 7 days.
Continue building the connection string following the instructions from the article above with one addition.
The Twitter Ads connection string requires the Account ID field to be filled in.
The Account ID can be obtained by logging into your Twitters Ads Manager https://ads.twitter.com/, clicking your company name in the upper right next to the logo/avatar and selecting Account Setting.
You'll find the Account ID in small print beneath "Name your account".
Follow the instructions in the other Twitter article and when you receive your approval email from Twitter, you should be able to access the Ads data.