2 references for creating slug

[2-man]

plugins.js:

module.exports = ({ env }) => ({
  // ...
  slugify: {
    enabled: true,
    config: {
      contentTypes: {
        book: {
          field: 'slug',
          references: ['title', 'released'],
          transformer(record, referenceFields) {
            const { title, released } = referenceFields;
            return {
               title: title,
               released: released.substring(0,4),
            }
        },
		},
      },
    },
  },
  // ...
});

I want slug to be title+year, in released reference there is a date from strapi, how to make it working? Now it is adding title+full date, not title+year

[ComfortablyCoding]

The transformer function has not been implemented yet.