I can't view the image because I don't have permission.
It's unlikely we'll be able to tell you even a rough age. Sometimes scorpions will molt very quickly while others will take months upon months to molt. Not to mention temperature and the right conditions change how long they will take to molt. So even if we knew what instar it is or how many molts it's gone through, we'd still have trouble telling its age. This makes knowing the size of the scorpion not that useful either.
The only sure way you can tell is if someone documented the scorpion since birth.
If the scorpion is already mature, all we can tell you is that it's an adult scorpion.