$user = Read-Host "Enter UPN"

$tap = New-MgUserAuthenticationTemporaryAccessPassMethod `
    -UserId $user `
    -BodyParameter @{
        lifetimeInMinutes = 480
        isUsableOnce      = $true
    }

Write-Host ""
Write-Host "User: $user"
Write-Host "TAP : $($tap.TemporaryAccessPass)"