LocalSend is a free and open source, cross-platform alternative to AirDrop for sending files securely over the local network. The Flutter app runs on Linux, Microsoft Windows, macOS, Android / Android TV, iOS, and Fire TV / OS.
The application doesn’t use any third-party servers and doesn’t require an Internet connection to work. For communication in the local network, it makes use of its custom LocalSend Protocol and HTTPS encryption. The data is sent securely over HTTPS, and the TLS/SSL certificate is generated on the fly on each device.
From Android, I see I can send files, media, text, and even app APKs to my Linux machine. It works pretty quickly and easily and does away with 3rd party cloud based transfers. It does not mirror screens or notifications, though.
See https://www.linuxuprising.com/2023/03/send-files-securely-over-local-network.html