$cert = New-SelfSignedCertificate -DnsName your.domain.com -CertStoreLocation "cert:\LocalMachine\My" -KeyLength 2048 -KeySpec "KeyExchange"
$password = ConvertTo-SecureString -String "Pa$$w0rd" -Force -AsPlainText
Export-PfxCertificate -Cert $cert -FilePath ".\your-certificate.pfx" -Password $password