The quickest fix is almost always a software update. The developers of SP Flash Tool add support for new chips in subsequent releases.
You are using an older version of a tool (like SP Flash Tool or Miracle Box) that was released before the MT68 chips hit the market. platform mt68 not supported on this version
If you are using "Download Only" and receiving the error, try switching the dropdown menu in SP Flash Tool to "Firmware Upgrade" The quickest fix is almost always a software update