Export-Certificate -Cert $cert -FilePath ".DevConfig.cer"

$mypwd = ConvertTo-SecureString -String "1234" -Force -AsPlainText

Export-PfxCertificate -Cert $cert -FilePath ".DevConfig.pfx" -Password $mypwd

$cert

Import-Certificate -Filepath ".DevConfig.cer" -CertStoreLocation cert:LocalMachineMy

$mypwd = ConvertTo-SecureString -String "1234" -Force -AsPlainText

Import-PfxCertificate -FilePath ".DevConfig.pfx" -CertStoreLocation Cert:LocalMachineMy -Password $mypwd

Install-Package WebConfigEncrypter -Version 1.1.0

<configProtectedData>
    <providers>
      <add name="Pkcs12Provider" thumbprint="91cb0b7c611e54f6bfd43c4d8d178b542bc6557e" type="WebConfigEncrypter.Pkcs12ProtectedConfigurationProvider, WebConfigEncrypter" storeLocation="LocalMachine"/>
    </providers>
  </configProtectedData>

aspnet_regiis -pef "connectionStrings" "." -prov "Pkcs12Provider"