This is all assuming it's a spinning disk and not an SSD, so ignore me if that's the case:
Given SAS drives are usually used in data centre storage array applications and 3TB disks have been kinda small for that use case for a fair while, there's a fairly high chance it was in heavy use for a good number of years. I'd bet it's probably well on its way to being a paperweight regardless of your connectivity situation.
If you do get it hooked up, don't store anything on it you wouldn't be okay losing.
Wanted a scratch disk to aggregate all my sensitive information thats scattered and duplicated on smaller disks and thumb drives. Would probably keep it as an ultimate backup too (I got a real backup).
My thinking was that usually those disks are swapped out after 5 years when failure rates starts to creep up, but there's still is some life left, largely enough for some fun.
For internal use, you can get a used PCIe SAS Host Bus Adapter fairly cheap BUT you need to do some research. Before you buy one you should confirm that there is a driver for the OS that you are using and that it is supported on your processor/socket/chipset. These cards are server hardware - many of them are not supported by Windows and/or are not compatible with consumer motherboards & CPUs.
And then two years down the line you lose all the data - the pictures, the savegames, the porn collection. Drives are the one thing that shouldn't be bought used
What you do is to look on the local used hardware sites, search for server, fet a cheap one with SAS interfaces, and now you have the start of a homelab.
SAS drives need a SAS controller. That can either be an adapter that you connect to a SATA port, or something topological bigger, such as a RAID controller. Both can be found relatively cheap.