Field instructions are the extra information you can add to a form field. This way, you can provide more context for your form visitors. You can also use this option to specify the exact input you require from them. All form fields that require user input have an instruction box where you can add some additional information.
Go to the Form Editor, select a field, and from the left-side panel type the information you want to add in the Instructions box.
By enabling the Show on click option, the extra information will display only when the visitor jumps to the respective field.