The belt / strap loop is installed using the supplied clip, 1 Allen Head bolt and the Allen Key.
This can either be installed on the flat back for a lower profile;
Or otherwise, you can place it on the side for greater access;
The case is designed to take the drone with the gimbal protector on. Just make sure when you lower the Mini 3 Pro into the case that you have the props and gimbal end pointing down.
The case is more than just something to wear. It can be used to store your drone all the time and it has a latch to hold in place so it won't come out during transport.
Your drone will stay well protected when you place it in your go-bag!