With the avaiable-regions endpoint, you an get a list of Data Center Locations that are available for the sites within your company. 
You can obtain the company_id from MyKinsta > username > Company settings > Billing details.
The company_id is also shown in the URL in MyKinsta, for example in the URL https://my.kinsta.com/?idCompany=bdd25d71-5706-4890-870f-1adda17c505d the company_id is bdd25d71-5706-4890-870f-1adda17c505d.
List of available regions
No or invalid API key provided to the request
Could not find the company or the user does not have permissions to retrieve data
Error occurred while retrieving available regions
{- "company": {- "available_regions": [- {- "name": "Dallas US (us-south1)",
- "region": "us-south1"
 }
 ]
 }
}