rendering but cant see the thumbnail?

[ShumGG]

this is how im using it:

 <Slider
                                minValue={50}
                                max = {100}
                                style = {{
                                    width: "100%",
                                    height: "4px", 
                                    backgroundColor: "red"
                                }}
                                handleRender = {() => {
                                    <div style = {{
                                        width: "30px",
                                        height: "30px",
                                        backgroundColor: "blue",
                                        border: "1px solid black"
                                    }}>

                                    </div>
                                }}  
                                ariaLabelForHandle = {"hola"}
                                handleStyle = {[{
                                    width: "30px",
                                    height: "30px",
                                    backgroundColor: "blue"
                                }]}
                            >

                            </Slider>

but when render i cant see the thumbnail