301 Redirect via nginx

🚀 Deployment
1

I am using nginx to force http to https for a custom domain for the app created using streamlit. But when I do 301 redirect, it throws the error - redirected too many times. Is there any way to redirect to custom url successfully? (when a user types *.herokuapp.com in the address bar, it should change to custom domain)
Here is my nginx conf file:
daemon off;
#Heroku dynos have at least 4 cores.
worker_processes <%= ENV[‘NGINX_WORKERS’] || 4 %>;

events {
   use epoll;
   accept_mutex on;
   worker_connections <%= ENV['NGINX_WORKER_CONNECTIONS'] || 1024 %>;
}

http {
    map $http_upgrade $connection_upgrade {
        default upgrade;
        '' close;
    }

    gzip on;
    gzip_comp_level 2;
    gzip_min_length 512;

   server_tokens off;

   log_format l2met 'measure#nginx.service=$request_time request_id=$http_x_request_id';
   access_log <%= ENV['NGINX_ACCESS_LOG_PATH'] || 'logs/nginx/access.log' %> l2met;
   error_log <%= ENV['NGINX_ERROR_LOG_PATH'] || 'logs/nginx/error.log' %>;

   include mime.types;
   default_type application/octet-stream;
   sendfile on;

   #Must read the body in 5 seconds.
   client_body_timeout 5;

   server {
      listen <%= ENV["PORT"] %>;
      server_name _;
      keepalive_timeout 5;

      location / {
          if ($http_x_forwarded_proto != 'https') {
              rewrite ^ https://$host$request_uri? permanent;
          }
          proxy_pass http://127.0.0.1:8501/;
      }

      location ^~ /static {
          proxy_pass http://127.0.0.1:8501/static/;
      }
      location ^~ /healthz {
          proxy_pass http://127.0.0.1:8501/healthz;
      }
      location ^~ /vendor {
          proxy_pass http://127.0.0.1:8501/vendor;
      }
      location /stream { # most important config
          proxy_pass http://127.0.0.1:8501/stream;
          proxy_http_version 1.1;
          proxy_set_header X-Forwarded-For $http_x_forwarded_proto;
          proxy_set_header Host $host;
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection "upgrade";
          proxy_read_timeout 86400;
      }
   }
}