Hello to everybody! Does anyone know how to get a custom category field to the website frontend? Thanks!

You need to fetch them separately. In a SuiteScript file, you need to do something like this:

Application.on('after:Category.get', function (CategoryModel, category) {
    var lookupResults = nlapiLookupField('commercecategory', category.internalid, [
        'yourcustomfield'
    ]);
    category.customfield = lookupResults.yourcustomfield
});

Hi Steve! Thanks for your response. I'll try that solution. Regards!