Converse.js automatic message translation

Question

How I can translate incoming message? I have made a plugin that listen on messageAdded event but I can't see the incoming message translated.

This is my code

chat.plugins.add('translate', {
    initialize: function () {
                var _converse = this._converse;

                _converse.on('pluginsInitialized', function () {
                    _converse.on('messageAdded', function (data) {
                        //console.log(JSON.stringify(data));
                        let message = data.message;

                        if(message.attributes.message) {
                            message.attributes.message = "test";
                            console.log(message.attributes.message);
                            console.log(data.chatbox);
                        }
                    });
                });
            }
        });

I can modify text message but the translated message is not displayed in chatbox