Often when buttons are missing for our PRSM clients I have discovered that the issue has been working on a narrow screen (less QBO is a little lacking in its adaptability to small screens and is super-greedy for screen real-estate. Even my 32inch screen on small resolution is too small often).
Collapse the menu on the left and you may suddenly see a whole lot more. Also look for the pop-our menu on the right and anything else that could be stealing space.

Remember too, that you will not be able to reach the settings gear from every screen. if you are in a transaction screen like invoicing then you won't see it - it will instead show you settings for that particular feature you are in.

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