Is "How do you set up an encrypted file on linux that can be mounted and accessed same as a hard drive." literally what you put into the search bar? if so, that's the problem.

try "mount luks encrypted file" or "luks file mount". too many words and any grammar at all will degrade your results. it's all about keywords

edit: after trying it myself i quickly realized the problem - luks related articles are usually about drives or partitions, not about files. this search got me what i wanted: "luks mount file -partition -filesystem" i found this article[1], which is in german (my native tongue), but contained the right information.

1: https://blog.netways.de/blog/2018/07/25/verschluesselten-fil...