First of all open the user's profile and check under "Tab Setting" whether the tab setting for "Account" object is "Tab Hidden or Default On/Off". If its "Tab Hidden" then you won't display on "Customize My Tabs" list. Change it to "Default On/Off" based on the requirement.
Can you please post the whole screenshot of the app?
I think you're on Site.com or Content app menu. By default, there is no account tab visible on that. You can use the App launcher to see your account object. If you still can't find the app make sure you've valid permissions to view the accounts tab.
Please check with the below screenshots, it may be hidden from the tabs.
First of all open the user's profile and check under "Tab Setting" whether the tab setting for "Account" object is "Tab Hidden or Default On/Off".
If its "Tab Hidden" then you won't display on "Customize My Tabs" list. Change it to "Default On/Off" based on the requirement.
https://help.salesforce.com/articleView?id=permissions_tab_settings_ref.htm&type=5
Thanks & Regards,
Ganesh Hembram
Can you please post the whole screenshot of the app?
I think you're on Site.com or Content app menu. By default, there is no account tab visible on that.
You can use the App launcher to see your account object. If you still can't find the app make sure you've valid permissions to view the accounts tab.
Please check with the below screenshots, it may be hidden from the tabs.
Thank you,
Ajay Dubedi