code:

    location /location1 {
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/htpasswd1;

        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
        proxy_set_header X-Forwarded-Host $http_post;
        proxy_set_header Host $http_host;

        proxy_pass [url]http://backend1.docker-network;[/url]
    }

    location /location2 {
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/htpasswd2;
        
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
        proxy_set_header X-Forwarded-Host $http_post;
        proxy_set_header Host $http_host;
        proxy_max_temp_file_size 0;

        proxy_pass [url]http://backend2.docker-network:1234/app;[/url]
        proxy_redirect [url]http://[/url] [url]https://;[/url]
    }