Red Gem Key : MM13
It seems you pressed the correct button.
It appears that the rule is to take the first letter of each word
and then count forward by the number
corresponding to that initial letter.
The first letter of Like is L, and L is the 12th letter of the alphabet.
If you count through the word “Like” from the beginning, the 12th letter is E.
Likewise, Share starts with S, which is the 19th letter,
so the 19th letter within the word is R.
Comment starts with C, which is the 3rd letter,
so the 3rd letter in the word is M.
You press the M button beneath the frame.
Soon, a part of the wall beneath the buttons opens,
and a red gem key treasure is revealed.
You take the treasure from the small space inside the opened wall and secure it.
After obtaining the treasure, you leave the area.
You have left the area.
You have successfully secured the treasure.
Congratulations!