HTTP Status 404 - NOT FOUND The requested resource [/Expense_Tracker/] is not available [duplicate]

HTTP Status 404 – Not Found

Message:

The requested resource [/Expense_Tracker/] is not available

Description:

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

My Project Structure is Also Correct and Code is also correct

then why it is not working ?

I try all the possible ways which are there on youtube but it didn't work please give me the way to find out error and solution for it.