Settings is no longer exists in TinyMCE

Question

I used TinyMCE version 5.10.2.
I add toolbar dynamically in version 5.10.2.

var tinyMceInstance = tinymce.get('tinymceid');
tinyMceInstance.settings.plugins += ' image';
tinyMceInstance.settings.toolbar[4].items.push('image');

But when I upgrade tinyMCE version from 5 to 6, settings is not available.
How can I add toolbar dynamically in tinyMCE version 6.x ?