Banggood dropshipping program its free and open but there is a kind of vetting process after you apply for an API key.
To start, you must register yourself as Banggood customer on this page.

After that, using the "Banggood dropshipping program registration form" you must require to be a dropshipping partner.

The information required are pretty the same you should provide to every dropshipping supplier on the market.
Once your store will be approved, you can access to the API panel.
Banggood divides the dropshipping account panel from the API panel, accessible with the same credentials but from a different url https://api.banggood.com
1. Browse the Banggood DropShipping section and click on "Apply Now"

2. Fill up all form steps

3. Get your Key from the API portal

Enter the Banggood API portal and you will see the API Key set showed on the home page.

Take note of your API key, it will be necessary on ApiDrop to activate Banggood as supplier.
Now that your API key has been approved, you must contact Banggood to their email address, indicating from which IP address you will call their API.
Here is a fast template you can copy and paste to speed up this task.
To: openplatform@banggood.com
CC: dropshipping@banggood.com
Subject: IP address whitelisting
---------------------------------
Dear Banggood,
My name is "XXXX YYYY" and my customer id is "ZZZZZZ". I am contacting you asking to whitelist my platform IP address 54.235.155.56 so I can start using your APIs.
Regards
XXXXXYYYYYY
---------------------------------