I did search to see if there was already an answer and there are some related answers but the code is different. I'm honestly not sure if this is HTML or Javascript. I have no experience with web development.
So this is what is pasted to my WordPress website.
<iframe src="https:"some address" style="border:none; min-height: 700px; width: 1px; min-width: 100%; *width: 100%;" name="site" frameborder="0" marginheight="0px" marginwidth="0px" width="100%" height="100%" referrerpolicy="unsafe-url" allowfullscreen></iframe>
Try adding scrolling (scrolling="no") attribute to remove scrolling.
<iframe src="https://stackoverflow.com/" style="border:none; height:100vh; width: 100%;" name="site" frameborder="0" marginheight="0px" marginwidth="0px" width="100%" height="100%" referrerpolicy="unsafe-url" scrolling="no" allowfullscreen></iframe>
as scrolling is deprecated I guess then we should go with CSS.
you can add this in your styleSheet or inside <style> tag in HTML page
iframe {
overflow-x:hidden;
overflow-Y:hidden;
}