From your first post you shared it looks like the learning lab you are following is not in sync with the sandbox and the feature you mentioned has been removed at some stage. To raise this issues i would create an issues with the learning lab team here https://github.com/CiscoDevNet/learning-labs-issues and ask for this to looked into. If the traffic generator is NOT in the learning lab exercise this text would need to be removed.
Hope this helps.
Please mark this as helpful or solution accepted to help others
Connect with me https://bigevilbeard.github.io
