Yes, your AM3+ 970 gaming motherboard supports M.2 SSDs.
Yes, your AM3+ 970 gaming motherboard supports M.2 SSDs.
I'm not sure if it's still an issue, but I managed to set up Windows from an NVMe Samsung 970 Plus using an adapter for gaming. It took some time, but it was quite straightforward. Just create a bootable installation USB and put it on the BIOS, switching it to UEFI mode. Then boot from the flash drive, delete all partitions on the NVMe, and select the unallocated space to install. It worked perfectly for me.