This is a tool used to dump NSP files from the games/dlc/updates you legitimately obtained from the e-shop. This is done through obtaining a nand backup via hekate, the required console specific keys via biskeydump from your switch, along with other keys via kezplez needed for hactool. It also requires googling for eticket_rsa_kek. For minimal ban risk, Delete your wifi connection profiles, put your switch into airplane mode, BACKUP YOUR NAND, run biskeydump, follow the instructions for running kezplez to get keys.txt, RESTORE YOUR NAND. At the end of this, you will then need hac disk mount to dump PRODINFO.bin, and mount the SYSTEM partition.