How to Allow only Valid Gmail users sign up in my PHP Laravel website?

I have this my sign up form in my php Laravel site which I think hackers and robots are making unnecessary sign-ups. But now, I want to allow only Valid Gmail users to create an account. I have configured this form but users with unknown mails are able to sign up. I’m a newbie in php Laravel codes. Someone should please help me configure this to achieve the goal. Thanks in advance. See form bellow.

 @csrf
                            <div class="form-group">
                                <input type="text" name="name" class="form-control" placeholder="{{__('Full Name')}}">
                            </div>
                            <div class="form-group">
                                <input type="text" name="username" class="form-control" placeholder="{{__('Username')}}">
                            </div>
                            <div class="form-group">
                                <input type="email" name="email" class="form-control" placeholder="{{__('Gmail')}}">
                            </div>
                            <div class="form-group">
                                <input type="tel" name="tel" class="form-control" placeholder="{{__('WhatsApp Number')}}">
                            </div>
                            <div class="form-group">
                                <input type="text" name="gender" class="form-control" placeholder="{{__('Gender')}}">
                            </div>
                            <div class="form-group">
                                <input type="text" name="item" class="form-control" placeholder="{{__('What do you want to buy? Please type in your issues here')}}">
                            </div>