It saddens me to have to point this out: Contrary to what a number of less scrupulous "passive income" YouTubers lead you to believe, the mazes from this site are not free to use for commercial purposes. If you are planning to use them in something you will sell, you need to get a commercial license. If you do not have such a license, you are committing a copyright infringement. For more information, see the link "Commercial use" above.