Why does the Add an organization endpoint of the API not include address fields?

Hey,
your issue is that you marked the content-type of your body as plain text. The API expects application/json. You can change the setting in your postman.

an example CURL might be:

curl --location 'https://{yourCompany}.pipedrive.com/api/v1/organizations?api_token={api_token}' \
--header 'Content-Type: application/json' \
--data '{
    "name": "esse fugiat ipsum",
    "owner_id": 56092724,
    "visible_to": "3"
}'

Also, I encourage you to check our Postman collection where predefined calls can be found.