Calibre doesn’t natively support reading DRMed files, but there are anti-DRM plugins which are trivial to install. You need to provide a legitimate Kindle serial number for Amazon DRM, as it uses that to de-encrypt the files. When you add the file(s) to your library, the plugin automatically runs as a file conversion. It basically converts it from a DRM-locked .epub/.azw3 to a DRM-free .epub/.azw3 instead. Since Calibre already has file conversions built in, the plugin simply uses that existing system to spit out a DRM-free version of the same file, then it adds that to your library instead.
This is how it works in Germany. Lots of their water bottles are made of glass, and end up with textured/worn rings along the bottle; The rings are from where it goes through the recycling machines to get prepped for the next use. The rings mean the bottle has been reused a lot, and has gone through the machines enough to get slightly worn.