Unable to create root site using New-SPOSite powershell cmdlet

Hi,

I faced an issue with New-SPOSite cmdlet. I can successfully create site collections under http://<tenancy>.sharepoint.com/sites/ managed path using New-SPOSite, but the same thing does'nt work if I try to create root site collection on http://<tenancy>.sharepoint.com. command restrns error message "New-SPOSite : Cannot create site https://<tenant>.sharepoint.com/ because root
site https://<tenant>.sharepoint.com/ does not exist or is not accessible."

How this task can be done via SharePoint Online Management Shell cmdlets?

thank you :)