How to turn off the automatic scrolling of ios SMS?

Ios SMS automatically scrolls off at the bottom.

1, Apple's ios SMS keeps scrolling because the vertical screen lock is not turned on.

2. Slide the page at the bottom of the phone to the far right, and you will see a circle with an open arrow on it. Click on the circle and a small lock will appear inside. At this point, the ios SMS will not automatically scroll horizontally.