Please refer to the implementaton guide here for details on WiFi4EU and portal setup:
The URL mentioned in the document is ""https://collection.wifi4eu.ec.europa.eu/wifi4eu.min.js" and the "Network Identifier" is something you will receive from the EU portal as part of Installation report, as mentioned in the WiFi4eu document. Please follow the section "4.Installation pre-requisites"->"WiFi4EU network UUID:" for the Network Identifier value to be configured.
Also as part of onboarding your Captive Portal with WiFi4eu you will have to do the following:
1. cnMaestro cloud server hosts it Captive portal through server :https://eu-w1-guest.cloud.cambiumnetworks.com so please ask WiFi4eu to add eu-w1-guest.cloud.cambiumnetworks.com in their whitelisted domains for allowing HTTPS GET requests to load their wifi4eu.min.js script and anything else as required and communicated by WiFi4eu.
2. Provide the set of public IP address used by your network deployment to WiFi4eu to let them whitelist in their firewall. The login page used by end guest clients will be posting some stats data to WiFi4eu servers and based on the source IP they would allow it through their firewall.
3. Once you have "Network identifier" and the URL configured on the cnMaestro Captive Portal and everything else set up then get one real wireless client on this captive portal. For this step I would recommend using your laptop and once you have loaded the cnMaestro hosted captive portal then copy the URL from the browser and share it with WiFi4eu for verification and hopefully the last step in the process for you network to be certified and approved by WiFi4eu. Please remember cnMaestro generates a new Captive portal URL each time you make a config change in the Captive portal so if at all you end up making any change please share the new URL with WiFi4eu. We plan to expose the Captive portal URL in cnMaestro to make this last step of sharing URL with WiFi4eu a bit easy.
In case you are using On Premises version of cnMaestro please use the domain/IP used used by your cnMaestro instead of eu-w1-guest.cloud.cambiumnetworks.com