Hi @ItzelWeller ,
Are you using the Free Canvas Account / Free-for-Teacher account? You can review the difference between the free and paid platforms here. According to the Canvas Free-for-Teacher FAQ page, you should be able to change the setting from Course to Public. If you can't then you will need to reach out to Canvas Support.
Just curious any reason you wouldn't add them as a user and enroll them as students? If you did this then they would get the true student experience and could really see how the product could work for employee training. Plus if they are in as "students" you can track the completion of "assignments", how long they have participated in the course....and a number of other items that you might find helpful. If it's a public course you won't have any of those details.
I hope this has been helpful.