Carousel component slides images, which you provide. Of course it only make sense, if you provide at least two of them, not only one.

Also, in your code snippet you are missing the closing tag for Carousel.Item:

<Carousel>
    <Carousel.Item>
        <img
            className="d-block w-100" style={{ height: '500px' }}
            src={img1}
            alt="First slide"
        />
    </Carousel.Item>
    <Carousel.Item>
        <img
            className="d-block w-100" style={{ height: '500px' }}
            src={img2}
            alt="Second slide"
        />
    </Carousel.Item>
    ...
</Carousel>

If it's still not working, please make sure you are importing your images correctly. Do you see the image when you only paste following code?

<img
    className="d-block w-100" style={{ height: '500px' }}
    src={img1}
    alt="First slide"
/>

If not, then the problem is not the Carousel component, but your images.