This plugin adds a button for inserting nonbreaking space entities at the current caret location (cursor insert point). It also adds a menu item Nonbreaking space under the Insert menu dropdown and a toolbar button.
tinymce.init({
selector: 'textarea', // change this value according to your HTML
plugins: 'nonbreaking',
toolbar: 'nonbreaking'
});The Nonbreaking Space plugin provides the following {productname} command.