To install your hot tub, you only need to worry about three things: a solid, level base to stand it on, power supply, and a hosepipe to fill it up. If you plan to sink the spa, there will be the added consideration of access on one or more sides for servicing, plus suitable drainage in the pit to remove overspill water or torrential rain. It’s recommended that you speak to your supplier for advice prior to making the decision to sink it into the ground & always request an installation guide, which should include specific advice on the model you have purchased. The experience of the supplier is always a valuable asset.