Please make sure you are logged in to your QuickBooks Online Accountant and look the ProAdvisor tab again, SM-Wajeeh. 

The primary causes for missing menus or display issues often include an unstable internet connection and a buildup of browser cache. Let's secure first a strong and stable internet connection. 

If the ProAdvisor tab is still missing, let's consider clearing cache. New cache can speed up browsing, and remove excessive buildup that causes unexpected behaviors. Then, you can also review if you're already using the supported versions of browsers. 

Once we resolved the missing ProAdvisor tab, we can proceed to know more about QuickBooks Accountant program and enhance your ProAdvisor profile. 

We are here to support you if you require any further assistance with this issue.