20 week ultrasound

I’m due for my 20 week scan soon and that’s when it’s planned for us to know the gender of the baby. But I’m nervous we won’t be able to find out the gender because of the way it’s positioned. Do the ultrasound techs wait until the baby switches positions to determine the gender or do they just put it off if the baby isn’t positioned right?

Wanted to plan a gender reveal for our families, but don’t want to have to put it off if the tech won’t be able to find the gender. Which is why I’m considering doing a private scan.