Searchable dropdown menu in Flutter

I have a radio buttons ListView that I want to transform it into a searchable dropdown menu.

I search and saw some videos on YouTube but it does not work with me, maybe because I'm new to Flutter, also my items were retrieved from Firebase and I could not list them in the dropdown menu. If anyone can help I will be thankful.

Here is my code:

  ListView.builder(
                              shrinkWrap: true,
                              scrollDirection: Axis.horizontal,
                              itemCount: selectedCategory!.tags!.length,
                              itemBuilder: (context, index) {
                                return SizedBox(
                                  width: MediaQuery.of(context).size.width *
                                      0.35, //  <= give specific width
                                  child: ListTileTheme(
                                    horizontalTitleGap: 0.2,
                                    child: RadioListTile(
                                      contentPadding: const EdgeInsets.only(
                                          left: 0, right: 0),
                                      visualDensity: const VisualDensity(
                                        horizontal:
                                            VisualDensity.minimumDensity,
                                      ),
                                      title: Text(
                                          selectedCategory!.tags![index],
                                          style: const TextStyle(
                                              color: textColor)),
                                      groupValue: tag,
                                      value: selectedCategory!.tags![index],
                                      activeColor: primary,
                                      onChanged: (value) {
                                        setState(() {
                                          tag = value;
                                        });
                                      },
                                    ),
                                  ),
                                );
                              },
                            )