Updated to NodeBB 1.12.1 today, which was extremely cumbersome for various reasons (you don’t want to update vips on FreeBSD, while GraphicsMagick crashes all the time, Python versions mix up and all dependencies break).
To set your own captive portal URL instead of the Google defaults:
settings put global captive_portal_https_url 'https://MYSERVER/generate_204'
The /generate_204 URL just needs to return 204:
# nginx
location /generate_204 { return 204; }
The setting won’t survive a reboot, so put it to a boot script.
Bild Link)