Redirect subdomain home page to another url of same subdomain

subdomain-redirect.conf

server {
        listen 80;
        root /var/www/html/subdomain/web-app/public;
        index index.php index.html index.htm index.nginx-debian.html;
        server_name app.web-app.com;

        location / {
            try_files $uri $uri/ /index.php?$query_string;
       }

        location = / {
           return 301 http://app.web-app.com/login;
        }

        location ~ \.php$ {
                include snippets/fastcgi-php.conf;
                fastcgi_pass unix:/var/run/php/php7.3-fpm.sock;
        }

        location ~ /\.ht {
                deny all;
        }
}