How to add rich text editor instead of textarea in the application form
The rich text editor is very useful to present the content of a field and thus allows rich text formatting, including bold, italics, underlines, font styles and sizes, colors, and alignment.
Step 1:
Go to MORE-> Application and Profile Builder
Step 2:
Once there, look for the section from where you want to add the text area and click the edit / pencil icon of the section.

Step 3:
Select Button "Add Field" and then give a field label / profile label and select the field type as "Rich Text Editor"

Step 4:
Save the section and here is how the rich text editor you will see.

The following video is from a previous interface but the information is still accurate. Make a note to select field type as "Rich Text Editor"