You have the permission to use these materials, with the crediting you mention.
The Tool Box has a Use Policy that addresses these situations, at https://ctb.ku.edu/en/use-policy. Your request is covered by provision #2 in that policy and it gives information on how to credit Tool Box use. Thanks so much for your thoughtfulness in reaching out with this question. We hope your training goes well and we hope the staff benefit from the resources that you share!
All the best,