SharePoint Online - You need permission to access this site [Solved]

Hi, Actually, I created office 365 free account and using sharepoint online. But while creating new target application in secure store, I am getting error as Application server does not have the latest key. Please guide me for this.

Thanks bro ..... thanks a lot . I had an assessment but couldn't access my material . Your video saved me .

How to get +New option on particular page?

+New option not showing on Atlanta why?