Why Ink to Text Disabled (Gray) in Draw Tab in OneNote?

Question:
Why do I write my handwriting in OneNote, and I find that the "Ink to Text" feature in the Draw tab is grayed out? Unable to click.

Answer:
The "Ink to Text" in Draw tab is use to convert handwriting to text.
The reason is OneNote wrong to judge. OneNote has treat the ink as drawing, not the handwriting. And this feature just convert handwriting to text.

Solution:
At first, select the handwriting, right click on them, click "Treat Selected Ink As" -> "Handwriting".
OneNote will convert ink to handwriting from drawing. And the "Ink to Text" will enable.
But it does not necessarily translate your handwriting into words successfully.

Drawing & Text & Image