Today, I have this issue, that i could not connect to a webservices, that are hosted by the Danish Tax Service, the URL where: https://emcstest.skat.dk
I got this warning:

Invoke-WebRequest : The request was aborted: Could not create SSL/TLS secure channel.

When running these commands

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
$WebResponse = Invoke-WebRequest "https://emcstest.skat.dk"

No matter what I did. But final I tested the webpage against SSLLabs
https://www.ssllabs.com/ssltest/analyze.html?d=emcstest.skat.dk
Found these ciphers

I then run these commands:

Enable-TlsCipherSuite TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Enable-TlsCipherSuite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Enable-TlsCipherSuite TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Enable-TlsCipherSuite TLS_AES_256_GCM_SHA384
Enable-TlsCipherSuite TLS_AES_128_GCM_SHA256
Enable-TlsCipherSuite TLS_CHACHA20_POLY1305_SHA256
Enable-TlsCipherSuite TLS_AES_256_GCM_SHA384

And finally I where able to access the webpage though powershell.