How to lock the font size and prevent the tеxtfrom auto-resizing?

Changing the size of your tеxt box will auto-resize your text to match the size of the tеxt box. 

To prevent this, we can lock the tеxt size by clicking the lock іcon beside the font size on the top panel.

Clicking on the lock icon again will unlock the font size, allowing your text to auto-resize with the tеxt box.