Mozilla has killed the SEND project for simple file sharing, but... you can set it up on your own server

The Send project, created by Tim Visee, is a file-sharing tool that utilizes cloud technology. It allows users to easily share files without the need to purchase any software. All you have to do is upload a file to the server, and in exchange, you'll receive a unique link to share. Send supports various file types and also allows users to set an expiration time for the links, which enhances the security of the shared data. Another benefit is the simple user interface, making it easy for even non-tech-savvy individuals to use. The project has gained popularity due to its simplicity, security, and user-friendliness.