TinyMCE for meta box

Hello all,

I know this question has been asked a lot but I can’t get a solution.

I have searched and every answer is different and involves lots of code. I am getting lost.

How in the later versions of wordpress can I add TinyMCE to my custom meta box?

Here is the HTML my functions file generated for my custom meta box:-

<div class="metaarea">
<label for="intro">Short introduction text:</label>
<textarea name="intro" id="tiny"><?php echo $intro; ?></textarea>
</div>

Thank you kind people