How to use the dropzone.dictInvalidFileType function in dropzone

var height = this.height;

            var self = this;

            this.dropzone = new Dropzone(this.$('.dropzone')[0], {
                acceptedFiles: 'image/*',
                addRemoveLinks: false,
                autoProcessQueue: true,
                // matches Spring Boot setting
                maxFilesize: 1,
                url: this.url,
                dictDefaultMessage: DEFAULT_MESSAGE,
                dictFallbackMessage: i18n['dropzone.dictFallbackMessage'],
                dictFallbackText: i18n['dropzone.dictFallbackText'],
                dictFileTooBig: i18n['dropzone.dictFileTooBig'],
                dictInvalidFileType: i18n['dropzone.dictInvalidFileType'],
                dictResponseError: i18n['dropzone.dictResponseError'],
                dictCancelUpload: i18n['dropzone.dictCancelUpload'],
                dictCancelUploadConfirmation: i18n['dropzone.dictCancelUploadConfirmation'],
                dictRemoveFile: i18n['dropzone.dictRemoveFile'],
                dictRemoveFileConfirmation: i18n['dropzone.dictRemoveFileConfirmation'],
                // check file dimensions before upload
                // see https://github.com/enyo/dropzone/wiki/FAQ#reject-images-based-on-image-dimensions
                accept: function(file, done) {
                    file.acceptDimensions = done;
                    file.rejectDimensions = function() {
                        done(i18n['customizations.fileDimensionsInvalid']);
                    };
                },
                init: function() {
                    // Register for the thumbnail callback
                    // When the thumbnail is created the image dimensions are set