Just tried to generate a self-signed SSL cert for my Synology DSM and the option is missing

Command to generate a self-signed cert to the Synology DSM

On WSL or Linux generate a self-signed cert as follows.

openssl req -x509 -newkey rsa:4096 -keyout mydsm.toggen.lan.key.pem \
-out mydsm.toggen.lan.cert.pem -sha256 -days 3650 -nodes \
-subj "/C=AU/ST=Victoria/L=Melbourne/O=Toggen/OU=IT/CN=mydsm.toggen.lan" \
-addext 'subjectAltName = IP:10.19.14.80, DNS:mydsm.toggen.lan, DNS:mydsm'

# Remember to replace mysdsm.toggen.lan with your fully qualified domain name
# Adjust -subj /C=Country/ST=State/L=City/O=Organization/OU=OrganizationalUnti/CN=commonNameHostname
# Adjust IP: and the DNS: entries to match your settings too.

Steps to upload a self-signed Certificate and Private Key To Synology

1. Login to your Synology. Open Control Panel
2. Click Security
3. Click the Certificates Tab
4. Click the Add button
5. Select Add a new certificate and click Next
6. Add a description e.g. MY SELF SIGNED CERT
7. Leave the Import Certificate radio option selected and check the Set as default certificate checkbox. Click Next

Note the -addext 'subjectAltName = IP:10.19.14.80, DNS:mydsm.toggen.lan' you can add as many DNS names or IP addresses as you like.

8. Upload the key mydsm.toggen.lan.key.pem and cert mydsm.toggen.lan.cert.pem to the Private Key and Certificate fields
9. Check that the old Default Certificate is NOT need and then Delete it by selecting it and clicking Action => Delete (The web server should restart and your browser should issue a warning about the cert not being trusted)
10. Finally add the mydsm.toggen.lan.cert.pem to your operating systems or browsers as a "Trusted Root Certification Authority"