You can choose between having your swim spa above ground, sitting on its own, surrounded by decking, set into a slope (cut and retain), partly in ground or fully in-ground. The second and third options require building a pit in the ground as the amount of plumbing and fittings under the spa makes installing a swim spa shell directly into the ground a risky choice.
Also, swim spas require a metal frame for support (which does not like being underground) and have the equipment (which requires access) inside the cabinet. This pit in turn requires drainage as it will fill up when it rains, making this option possible but relatively expensive.
This is why most people have their swim spa above ground and consider building steps or a deck around it if they want a more landscaped look. Having the swim spa completely above ground is another option that allows you to fence only the steps (as long as the swim spa is over 1200mm high the height of pool fencing).