Good day @hmoi KKA ,
This forum is for English discussions. If you can translate your question and make discuss the issue in English, then please do so. If you prefer to discuss in Japanese then you should use one of the Japanese forums. The Japanese forums are in the MSDN system. The following article can help you find the best forum for your needs:
https://social.technet.microsoft.com/wiki/contents/articles/34901.list-of-forums-by-languages-categories-and-field-of-discussions.aspx
Regarding your question,
Docs-Learn-Reference-Host a web application in Azure App Service-Exercise In the step to create a web app in the Azure portal, when I click Enable Sandbox, I get the error ``Account validation failed "We were unable to validate your account and suspended your access to the Learn sandbox." I can't solve the problem by looking at the "Troubleshooting Guidance".
What could be the reason for account verification failure?
Microsoft Learning have a totally separate forum system (not one of these in the link above. It is only in English as much as I know. Your question is very comment and you can find response there:
https://trainingsupport.microsoft.com/en-us/tcml/forum