BunnyCDN, DigitalOcean and AWS all offer REST APIs to Upload/Delete pages.
There was once a HTTP standard called WebDav IIRC but it seems rarely implemented. Why haven't these sites tried that direction if they wanted HTTP-Backed security measures?
Upload/Delete as REST is usable though.
WebDAV is still a valid thing, and used quite more often than most people know. Its not known because it lives deeply embedded within apps and systems, and not something that is often visible to users. Case in point, a little thing called Google Drive makes use of WebDAV, so does NextCloud, etc.
WebDAV's not dead yet! (With apologies to Monty Python. ;-)
They give you a free subdomain with HTTPS (Let's Encrypt). If you want, you can bring your own domain too.