In Wordpress, click on "Plugins":
Search "iframe". Select iframe by webvitaly:
Install this plugin. One done, go to your page and add in a "Shortcode" element:
Here's copy and paste the code that can be found in the "Integrate" tab under "Embedded your flow":
It's recommended to specify the width and height within this, as Wordpress has many conflicting features that may override this. The effects of how Wordpress turns up will be affected by the container of your Wordpress block itself.