I would like to modify a custom module that I bought. This module let customer ask for a quote. In the backend, I added a textearea for each product requested on quote. I would like to load this field using WYSIWYG instead of a simple textearea. I saw few examples on Internet but it's not working. The section where I added my textarea is added as block in the layout xml file. The form is not constructed with a php _prepareForm() function using addField() but with a simple .phtml template file to display each field.
Do you have some clue to achieve this? The supplier of the module told me that I have to add necessary librairies (JS and CSS) in the head with layout.xml.