Install this certificate to trust all *.charliehub.net and *.charliehub.internal services.

curl -O https://pki.charliehub.net/ca.crt sudo security add-trusted-cert -d -r trustRoot \ -k /Library/Keychains/System.keychain ca.crt
Tap Install on this device above (or scan the QR code on another device). Go to Settings → General → VPN & Device Management to complete installation, then enable trust in Settings → General → About → Certificate Trust Settings.
curl -o /usr/local/share/ca-certificates/charliehub-internal-ca.crt \ https://pki.charliehub.net/ca.crt sudo update-ca-certificates
Invoke-WebRequest https://pki.charliehub.net/ca.crt -OutFile charliehub-ca.crt certutil -addstore Root charliehub-ca.crt
Download ca.crt, then go to Settings → Security → Install a certificate → CA certificate and select the downloaded file.