Hey i need a little guidance about how to check the value of a radio button which is in a form in portal and i want the selected radio button to populate in the model while confirming.

Here is my code of passing rest of the data but m unable to pass the radio button. Got any idea?

    _create_advance: function () {
       return this._rpc({
            model: 'hr.advance.salary',
            method: 'create_advance_portal',
//            var pay =  document.getElementById('payment').checked;
//            var result= pay.value;
//            if (result === true) {
//                console.log('Partially');
//                new_result = $('.new_advance_form .partially').val();
//            }
//            else{
//                new_result = $('.new_advance_form .fully').val();
//            }

            args: [{
                request_amount: $('.new_advance_form .request_amount').val(),
//                payment: new_result, This was my radio button
                payment_start_date: $('.new_advance_form .payment_start_date').val(),
                reason: $('.new_advance_form .reason').val(),

            }],