add plugin to vendor dashboard

Hello.
My purpose is add one plugin into the vendor dashboard’s product->add product->description part(mode of visual edit) so that vendors also can use the plugin to edit visual text.

1.Why some plugins can be added in vendor dashboard’s left menu and can be used(one plugin already set automatically after install it in my WP)?
(and why the others which already set up in admin’s menu page are not?)
2.How can I add plugin button to vendor dashboard’s add product visual mode toolbar section?
(please tell me what php file make the vendor dashboard->add product->description part module. I think some where in this plugin must exist’ wp_editor() function’. If exist, I can switch its ‘teeny = true’ variable to”teeny = false’. But cannot find out where the define the module’s php file in hole ‘wc vendor’ plugin folder!)
*Or do you have any other ideas can resolves this?

https://wordpress.org/plugins/wc-vendors/