@Dzmitry_Baranau use beforeUpdate lifecycle method with condition “published_at != null” like that:
async beforeUpdate(params, data) {
const news = await strapi.query("news-item").findOne({ id: params.id });
const newsUpdated = { ...news, ...data };
if (newsUpdated.published_at != null) {
if (newsUpdated.user == null) {
const err = new Error("Please set up User field");
const boomError = Boom.boomify(err, {
statusCode: 422,
});
throw boomError;
}
}
}