Flutter Error This widget has been unmounted, so the State no longer has a context (and should be considered defunct)

When i click on the text this exception appears: FlutterError (This widget has been unmounted, so the State no longer has a context (and should be considered defunct). Consider canceling any active work during "dispose" or using the "mounted" getter to determine if the State is still active.)

Future addToList({
required String name,
required int price,
required String imgUrl,
required String quantity,
}) async {
    final docShopList = FirebaseFirestore.instance.collection('shoplist').doc();
    final shopList = ShopList(
        id: docShopList.id,
        name: name,
        price: price,
        imageUrl: imgUrl,
        quantity: quantity);
    final json = shopList.toJson();
    await docShopList.set(json).then(
          (value) => showDialog(
            context: context,
            barrierDismissible: false,
            builder: (BuildContext context) => AlertDialog(
              title: const Text(
                'El producto se ha añadido al carrito',
                textAlign: TextAlign.center,
              ),
              actions: <Widget>[
                TextButton(
                    onPressed: () {
                      Navigator.pop(context);
                      
                    },
                    child: const Text('OK'))
              ],
            ),
          ),
        );
  }

The TextButton:

                      TextButton(
                        onPressed: () {
                          addToList(
                              name: widget.products.name,
                              price: widget.products.price,
                              imgUrl: widget.products.imageUrl,
                              quantity: quantity ?? '1');
                          widget.callback(2);
                          widget.controller!.resumeCamera();
                          Navigator.pop(context);
                          Navigator.pop(context);
                        },