Send Teams chat via Graph PS

Send-TeamsChat.ps1

Import-Module Microsoft.Graph.Teams

$params = @{
    ChatType = 'oneOnOne'
    Members  = @(
        @{
            '@odata.type'     = '#microsoft.graph.aadUserConversationMember'
            Roles             = @('owner')
            'User@odata.bind' = "https://graph.microsoft.com/v1.0/users('UPN')"
        }
        @{
            '@odata.type'     = '#microsoft.graph.aadUserConversationMember'
            Roles             = @('owner')
            'User@odata.bind' = "https://graph.microsoft.com/v1.0/users('UPN')"
        }
    )
}

$chat = New-MgChat -BodyParameter $params

$body = @{
    ContentType = 'html'
    Content     = "Trying something new <at id='0'>Zach</at>"
}
$mentions = @(
    @{id            = 0
        MentionText = 'Zach'
        mentioned   = @{

            User = @{
                id = $z.Id
            }
        }
    }
)

New-MgChatMessage -ChatId $chat.Id -Body $body -Mentions $mentions