You can use the UseCredentialsFrom command in PowerShell to reuse the previously entered credential in the -browser window to connect to another site.
This eliminates the need to re-enter the same information every time you have a new connection.
$srcsite = Connect-Site -Url "https://test.com/sites" -Browser
$srcsite1 = Connect-Site -Url "https://test.com/sites1" -UseCredentialsFrom $srcsite
$dstsite = Connect-Site -Url "https://test.com/sites2" -UseCredentialsFrom $srcsite