Dymo labelwriter 450 printer prints label wrong

suppose you have installed the software required by the Dymo labelwriter 450 printer quick start user guide
and you have connected power cord and connected printer to your computer via USB
when you first time launch the software, most likely you get this screen:

since the label roll is pre-loaded, you probably happily click Add > Text to the label area on screen, then click the blue button Print: dah..dah..,

at least in my case, it prints the wrong direction. I tried:
1. select the text box on label, then in left pane, change text format: horizontal, vertical..., not working.
2. change layout: none, 90, 180, 270, not working...
3. searched and watched some youtube videos, they mentioned change label type, but when click the up arrow at bottom right corner of screen,
there is only one label type: White Address Labels 30251
so still not working....
wasted 10+ labels, I felt guilty and stupid, almost gave up.

final try: click New at top left menu bar, a wizard appears, Select printer > select label type, here it is! the pre-loaded label type is 30334 (which is printed on the back of label), but when the software is first launched, the default is White Address Labels 30251, that's why it prints the wrong direction.
finally it works, it worrrrrrrrrrrrrrrrrks !
but this so critical operation is not mentioned in their user guide, which is stupid and also make their user feels stupid, even though such a good useful gadget.