Summary:
In Bedrock Edition, there isn't an "FOV effects" slider like in Java Edition. This function adjusts the strength of all FOV changes; for example, freezing, entering/exiting liquids, speed effects, etc.
Instead, there's only a toggle option labeled "FOV Can Be Altered By Gameplay." This toggle functions similarly to setting the FOV to either 0% or 100% on Java Edition. The feature allowing adjustable FOV was introduced to Java Edition in version 1.16.2. Relates to MCPE-159182.

Steps to reproduce:

1. Open settings.
2. Try finding the "FOV effects" slider.

Observed results:
"FOV effects" slider is missing.

Expected results:
"FOV effects" slider is in the settings.

Screenshots:
Java