Good morning Peter, it works!
When I followed your link for “Using the Raspberry Pi as an access point to share an internet connection (bridge)”, towards the end it tells you “The access point setup is almost the same as that shown in the previous section. Follow all the instructions in the Configuring the access point host software (hostapd) section above to set up the hostapd.conf file and the system location, but add bridge=br0 below the interface=wlan0 line, and remove or comment out the driver line. The passphrase must be between 8 and 64 characters long.” Following this it includes uncommnenting the line net.ipv4.ip_forward=1. But it’s not straight forward and I will have a look at your documentation and instructions once I prepared our pool today. 🙂
I just checked my LAN connections on my router to identify the PWS IP and edited your command line above. After npm start I got the following: