When the functionality of converting written text to computer characters in my One Note appeared in gray I immediately assumed something was not working correctly instead of thinking «Hey I haven’t used One Note in like 8 years, maybe something has changed in it’s functionality».
Although the image is in spanish the highlighted section means «Ink to text»:
Ink to text disabled in One Note
So I’ve started searching information about this behaviour on the Internet (as usual) finding threads like this, this one, or this but none of them solved the issue quickly, of course because there were no issue at all!
The only thing I had to do was, first write something and then select Select objects or write text, then drag the mouse selecting the written text and finally the option became available:
It wasn’t so intuitive but I discovered it by using the tool a little more trying to figure it out, it’s Microsoft folks, sometimes they change things you were used to so I help this little post solves the needs of others like before falling in despair.