Older PowerShell versions do not use TLS1.2 as the default version during the SSL handshake. When the API requires TLS1.2 the error message appears:
Invoke-WebRequest : The request was aborted: Could not create SSL/TLS secure channel.
To force PowerShell to use TLS1.2 during the SSL handshake, issue this command before executing the Invoke-Webrequest
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12;
Invoke-WebRequest ....