[ Solved ] User does not have sufficient permission for site
My WordPress blog has been zero visitors since the error occurred.
In order to solve this problem, I identified and corrected the problem to solve it.
I proceeded with the reset at Site Kit.
Then, the plug-in was completely deleted.
After downloading, installing, and authenticating the Site Kit, it came out normally.
Since then, I had to do all the settings.
Ad-sense, Google Analytics, etc.
Additional authentication and authority registration were made on the way.
All parts come out normally.
And the number of visitors is expected to increase.