Good to know:
metadataBase is typically set in root app/layout.js to apply to URL-based metadata fields across all routes.
All URL-based metadata fields that require absolute URLs can be configured with a metadataBase option.
metadataBase can contain a subdomain e.g. https://app.acme.com or base path e.g. https://acme.com/start/from/here
If a metadata field provides an absolute URL, metadataBase will be ignored.
Using a relative path in a URL-based metadata field without configuring a metadataBase will cause a build error.
Next.js will normalize duplicate slashes between metadataBase (e.g. https://acme.com/) and a relative field (e.g. /path) to a single slash (e.g. https://acme.com/path)
Default value
If not configured, metadataBase has a default value