Write in a text box that is shows by clicking a check box.

In a PDF form (Acrbat DC) I want that if one check box is active, another text field shows and is fillable. I changed the options of the check box so it displays or hides the text field. I also changed the text field to be hidden by default. The show/ hide works but I cannot fill in the text in the shown textfield.

Thanks for helping me.