App Store Connect API Access

Part 1:  Generating an API Key

1. Log in to App Store Connect

2. Select Users and Access.

3. Select the API Keys tab.

4. Click Generate API Key or the Add (+) button.

5. Enter a name for the key. The name is for your reference only and is not part of the key itself.

6. Under Access, select the role "Finance" for the key.
The roles that apply to keys are the same roles that apply to users on your team.
See role permissions

7. Click Generate

The new key's name, key ID, a download link, and other information appear on the page. 

<1> Issuer ID. 
<2> Key ID. 
<3> Click "Download API Key" to download your API private key. The download link appears only if the private key has not yet been downloaded. Apple does not keep a copy of the private key.  So you can download it only once. 

Part 2:  Finding your Vendor ID

8. Go to Sales and Trends

9. Go to Sales and Trends Reports on the left side

9.  Find your Vendor ID at the top left under your Legal Entity Name