Java - PDFBox get String value from Radio button

Question

Here is my following code :

for (PDField field: listFields) {
                    
                            if (champs instanceof PDRadioButton) {
                                
                                PDRadioButton pdRB = (PDRadioButton) champs;
                                System.out.println(pdRB.getValueAsString());
                            
                            }

I have a pdf with a radio button selection.

O : Group 1 O : Group 2 O : Group 3

I want to get the String value (like Group 1)

But i can only get the int value "1 , 2 or 3" i tried every PDRadioButtion function that return a String and no one give me "Group1, .."

Do you have any solutions ? Does the problem come from the PDF form ? Thanks !