How can I add a DELETE Button in a public form ?

How can I add a DELETE Button in a public form ?

Hello and thanks in advance if someone can help me.

I work in a University and I often prepare public forms to permit students to book in activities.

I need to add a delete button to allow students (If the student change idea) to delete from a subscription.

Is it possible ?

Thank you very much for an ipotetic solution.

Diego