Well I got a solution. I added a .htaccess file in root. And use this code there.
<IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.html$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.html [L] </IfModule> Now it works perfectly here !!!

From the [vue.js documentation page][1]:
> When using history mode, the URL will look "normal," e.g. http://oursite.com/user/id. Beautiful!
> Here comes a problem, though: Since our app is a single page client side app, without a proper server configuration, the users will get a 404 error if they access http://oursite.com/user/id directly in their browser. Now that's ugly.
> Not to worry: To fix the issue, all you need to do is add a simple catch-all fallback route to your server. If the URL doesn't match any static assets, it should serve the same index.html page that your app lives in. Beautiful, again!
##Apache
<IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.html$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.html [L] </IfModule>

[1]: https://router.vuejs.org/en/essentials/history-mode.html