post https://{tenanturl}/v3.0/PasswordDictionary/CSV/import
See https://tools.ietf.org/html/rfc4180, Common Format and MIME Type for Comma-Separated Values (CSV) Files, in a spreadsheet safe form.
The first line in the CSV file must contain the names as the column headers. Use the /v3.0/PasswordDictionary/CSV/headerNames API to get the list of header names.
The CSV file must use the UTF-8 character set.
Only one CSV import request can be running for the specified tenant. This includes the user and group import requests
The maximum file size is 20 MB.
Values that contain a special character (i.e. comma) must be enclosed in double quotes.
Entitlement required: managePwdPolicy (Manage password policy).