Krunal's answer works in most cases. But if you do not have this set of upper limit, the white view will be under the home indicator line.

In my design, the white look had only leading, final, lower and upper limits. I had to add another view in the form of a white view (now this view will be a white view), include a guide on planning a safe area for the external white view, and set limits for the field / safe area to get this thing for all devices, including X.
NB: the height limit should be set for the appearance / button (in my case), and not for appearance. Autolayout will do the job right for you on your iphone X.

Here's what it looks like on iphone X and other phones. iPhone SE:

iPhone X:

Hope this can help someone. :)
abhi1992
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