Restic is a modern backup program that can back up your files:

from Linux, BSD, Mac and Windows

to many different storage types, including self-hosted and online services

easily, being a single executable that you can run without a server or complex setup

effectively, only transferring the parts that actually changed in the files you back up

securely, by careful use of cryptography in every part of the process

verifiably, enabling you to make sure that your files can be restored when needed

freely - restic is entirely free to use and completely open source

Deduplicating archiver with compression and encryption

Free backup software to store encrypted backups online

Backups and Nextcloud servers online

To set up a Time Machine server on a Mac in your local network, it is necessary to enable the SMB file server of macOS that will share the data for access. SMB is the Server Message Block protocol recommended by Apple for file sharing. It is also being used by other operating systems such as Microsoft Windows® or Linux®. As of OS X 10.9 Mavericks, this protocol has become the standard for file services on the Mac.