In Nginx, I want to redirect the sub-domain request with request-uri to sub-domain but if there is no request-uri in it should redirect to main domain - nginx

Question

My problem statement :
my domain : example.com
sub-domain : main.example.com
when we will access:
1. http://main.example.com/xyz or https://main.example.com/xyz :
It must be redirect to https://main.example.com/xyz
http://main.example.com or https://main.example.com :
It must be redirect to https://www.example.com
I am using nginx. What will be configuration file for Nginx server?
My current setting is :
server{
listen 443;
ssl on;
ssl_certificate /var/www/html/demo.crt;
ssl_certificate_key /var/www/html/demo.key;
server_name main.example.com$request_uri;
location / {
root /var/www/html;
index index.html index.htm;
try_files $uri $uri/ /index.html;
}
}
server {
listen 80;
server_name main.example.com$request_uri;
return 301 https://main.example.com$request_uri;
}
server {
listen 80;
server_name main.example.com;
return 301 https://www.example.com;
}
server {
listen 443;
server_name main.example.com;
return 301 https://www.example.com;
}

Answer 1

Try
server{
listen 80;
listen 443 ssl;
server_name main.example.com;
ssl_certificate /var/www/html/demo.crt;
ssl_certificate_key /var/www/html/demo.key;
location / {
proxy_pass https://www.example.com;
}
location ~ ^(/.+) {
return 301 https://main.example.com$1;
}
}
http://nginx.org/en/docs/http/configuring_https_servers.html#single_http_https_server