Please follow the steps below in order to add " Read only" text to your form.
From the list ribbon click "KWIZ Apps"
Click on a gear icon besides "Form Layout"
Under "Groups/ tabs", press "new group"
In the "name" field add the name of the Group
In the Groupe Layout add a row, and choose "Text cell"
Press "Edit content" and add the instructions/phrase you want to appear under the field. This Text cell will appear "Read only" in the form. For example: I entered "Please make sure to add you full name", in the Text Cell content box.
This is how your "Read only" text will appear on the form.