Good question! A lot of people just post their drone-stitched low resolution panoramas to social media like Facebook, but that's a real shame when you're using a professional drone like Inspire 3 which can capture a 3Gpx panorama. I use AmazonS3 for hosting and a Wordpress website for featuring the aerial tours. That means you can host the maximum resolution. I host 500,000px wide panoramas like that in full resolution, down to 648Mpx panos from a smaller drone. This website mentions several hosting options if you don't want to manage the hosting yourself:
5 Best Platforms to Upload Your 360 Photos | VeeR VR Blog They mention Facebook and I don't know if all those hosts are active.