Clightning with BTCpay server failed I have setup WooCommerce and BTCpayserver in Google cloud, and synced. Test to buy with BTC seems to work.

Adding Lightning fails:
I modified in BTCpay Lightning nodes in the Store management 
"clicking here" added the connection string:

Type=clightning;server=unix://etc/lightning_bitcoin/lightning-rpc


I submit and came back to test connection, it fails:

Error: Error while connecting to the lightning node via 34.73.111.47:9735 (The operation was canceled.)operation was canceled.)


I used during setup the following Exports:

 export BTCPAY_HOST="btcpay.elmit.com" 
 export NBITCOIN_NETWORK="mainnet"
 export BTCPAYGEN_CRYPTO1="btc"
 export BTCPAYGEN_REVERSEPROXY="nginx"
 export BTCPAYGEN_LIGHTNING="clightning"
 export BTCPAYGEN_ADDITIONAL_FRAGMENTS="opt-save-storage-xs;opt-save-memory" 
 export BTCPAYGEN_ADDITIONAL_FRAGMENTS="$BTCPAYGEN_ADDITIONAL_FRAGMENTS;opt-add-woocommerce"
 export WOOCOMMERCE_HOST="store.elmit.com"


Did I miss something?
I found it. The port 9735 is not open to the public. 

Go to google cloud console

Home -&gt; VPC network -&gt; Firewall rules

+ Create firewall rule:

Name      Type    Targets   Filters          Protocols / ports  Action  Priority    Network
lightning Ingress Apply to all  IP ranges: 0.0.0.0/0 tcp:9735       Allow   1000        default