using `n how can i add two empty line (two carriage return), between these two lines in the output file?

hi friends

using `n  how can i add two empty line (two carriage return), between these two lines in the output file?

PS C:\> $env:COMPUTERNAME|add-contentc:\file.txt

PS C:\> $Env:USERDOMAIN  | add-content c:\file.txt

 i tested many forms but didn't work.

thanks