@尚典 青村 , Thanks for the great question.
As mentioned in the UserVoice “This is something we would like to bring in the future, but we cannot provide a timeline at this time.”-You may upvote the post.
For customization, you may edit web.config
file located in D:\home\site\wwwroot
folder.
You may try this code (copied below), answer from a similar SO discussion thread.
For more details on customErrors flag.
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<httpErrors errorMode="Custom" defaultResponseMode="ExecuteURL">
<remove statusCode="404" subStatusCode="-1" />
<error statusCode="404" path="/404.asp" responseMode="ExecuteURL" />
</httpErrors>
</system.webServer>
</configuration>
If your requirement fits, you may use Application Gateway, which allows you to create custom error pages instead of displaying default error pages. You can use your own branding and layout using a custom error page. Checkout this doc ‘custom error’ section for more details.