Unmuting a particular participant

How can I enable Request to Unmute a Participant?  I followed the steps below, but it doesn't seem to be working. 

To enable the pre-approved consent to unmute feature for all users in the account:

1. Sign in to the Zoom web portal as an administrator with permission to edit account settings.
2. In the navigation menu, click Account Management then Account Settings.
3. In the Meeting tab, navigate to the Request permission to unmute option (under the In Meeting (Advanced) section) and verify that the setting is enabled.
   Note: If the setting is disabled, click the toggle to enable it. If a verification dialog displays, choose Turn On to verify the change.
4. (Optional) If you want to make this setting mandatory for all users in your account, click the lock icon, and then click Lock to confirm the setting.
   Note: Users must have client/app version 5.2.1 or higher to see the option when scheduling.