I'm using DNS-less instance for the Yggdrasil local network,
in this case I set null because IPv6 makes 500 error:
'url' => null,
but also when applying solution from here
I got another error, because JS dependency fails with exception:
webpack://flarum/node_modules/mithril/pathname/build.js
// Returns `path` from `template` + `params`
module.exports = function(template, params) {
if ((/:([^\/\.-]+)(\.{3})?:/).test(template)) {
throw new SyntaxError("Template parameter names must be separated by either a '/', '-', or '.'.")
}
and some other extensions have this issue.