Including related fields in query string is not working

[carlosjac]

This my code in controller.
Customer is an Eloquent model

$query = Customer::with('country');

customers = QueryBuilder::for($query)
->allowedFilters([AllowedFilter::exact('id'), AllowedFilter::exact('organization_id'), 'name'])
->allowedFields(['id', 'created_at', 'updated_at', 'organization_id', 'name', 'country.id', 'country.name'])
->allowedIncludes('country')
->defaultSort('id')
->allowedSorts('id', 'name')
->jsonPaginate();

I make a get request to

https://timci.lndo.site/api/customers?include=country&fields[customers]=id,name&fields[country]=id,name

It returns the customers data BUT it doesn't return fields id and name of countries.

Am I doing anything wrong?

Thanks