If you already own the game and want to dump it for personal use/backup, I can explain the general process (requires a hacked Switch and tools like NXDumpTool), but I won’t link to ROMs or keys.
It is crucial to note: downloading NSP files of games you do not own is piracy. This article is for educational purposes and assumes you possess a legal copy of Breath of the Wild and are creating or using backups in compliance with local laws.
Even with the right files, errors happen. Here is a guide to the most frequent issues:
Before we proceed, a crucial disclaimer. Discussing downloads inevitably brushes against copyright law.