@BIRAT ADHIKARI Thanks for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this.
As @Ben Gimblett pointed out we didn't find any screenshots attached to this thread can you check and try uploading those screenshots again.
I would suggest you run the
Web App down detector in Diagnose solve problems of you webapp to understand or identify the cause.
You can also try enabling the diagnostic logging to your app service and review the application logs.
Feel free to reach to back to me if you have any further questions on this.