Error converting Office 365 user mailbox to shared

Hi,

I'm trying to convert one user mailbox to shared mailbox on Office 365.

Get-Mailbox -identity name@mydomain.com.br | set-mailbox -type "Shared"

But getting error:

"A parameter cannot be found that matches parameter name 'type'."

On the Web Exchange Admin I click on convert several times and also don't converting.

Thanks.