Height problem

Hello:
When I run the code below on another site, the height appears at half. I have to enter the height value. This is very difficult in every form.

How can we edit the code so that the height setting is 100%?

thanks

      <iframe src="https://www.pexpe.com/?cff-form=15" style="width:100%; height:100% overflow: hidden; border: none;" scrolling="no"></iframe>