After writing your text in the window, click OK in that window, the window disappears, the text is hanging at the cursor crosshair then. Move it to where you want it in the drawing space, it might seem to disappear on the way, but when you click the mouse at the target position, it will be dropped there and is visible. You can drop it multiple times. Type "Esc" to end the function.
Maybe you just have to select a bigger size for the font, default is 1. Try 20, or even 100, just to see if it helps. Or zoom in very far to see if there is text. The proper text size depends on the other settings in the drawing.