Magento 2 : how to use TinyMCE v4 in Magento 2.2.6?

Have you seen this

https://github.com/pavelleonidov/magento2-tinymce4

This should work. Only for Magento 2.1 and 2.2

Run below commands to use that version.

composer config repositories.magento2-tinymce4 git [email protected]:pavelleonidov/magento2-tinymce4.git;
composer require pavelleonidov/module-tinymce4
php bin/magento setup:upgrade && php bin/magento setup:di:compile