Asking permission from a copyright owner to use their work should be your last resort.
It's always best to first try to
- use a work in the Public Domain or with a Creative Commons license,
- use a work according to the Classroom Teaching Exemption,
- use a work in a way that would be protected under Fair Use, or
- find an alternative work that would satisfy one of the above - contact a librarian if you'd like help with this, or explore the Free to Use tab on the left.
If none of the above apply, then you can consider asking the copyright owner for permission to use their work directly, but this comes with challenges:
- You are asking the copyright owner to waive the privileges and profits that would result from you and your students paying for copies through the normal channels. The copyright owner may likely deny your request for this reason.
- The copyright owner may take weeks or months to respond, if they respond at all. It will probably be more timely for you to try one of the other options listed above.