Terminology:
βAltβ refers to the βOptionβ key ( β₯ )
If you have enabled βUse F1, F2, etc. keys as standard function keysβ under βKeyboardβ settings in βSystem Preferencesβ then omit the βFnβ key from the keyboard shortcuts shown in this article.
Note: If this does not work it could be because your computer settings are managed by someone else (an IT department or administrator for example). If this is the case you will need to contact them to access these settings or for further help.