Cannot start nginx service affter config with mattermost

Dear guys!
i setup mattermost 5.28 and postgresql12
my ip private 192.168.171.158, affter install sucessfull i can enter 192.168.171.158:8065 and that working
but then i install nginx and use config of mattermost to forward port 8065 to 80, but nginx service not working, can help me this thing?

upstream backend {
   server 192.168.171.158:8065;
   keepalive 32;
}

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mattermost_cache:10m max_size=3g inactive=120m use_temp_path=off;

server {
  listen 80 default_server;
  server_name   chatsama.ddns.net;
  return 301 https://$server_name$request_uri;
}

server {
   listen 443 ssl http2;
   server_name    chatsama.ddns.net;

   http2_push_preload on; # Enable HTTP/2 Server Push

   ssl on;
   ssl_certificate /etc/letsencrypt/live/{domain-name}/fullchain.pem;
   ssl_certificate_key /etc/letsencrypt/live/{domain-name}/privkey.pem;
   ssl_session_timeout 1d;

   # Enable TLS versions (TLSv1.3 is required upcoming HTTP/3 QUIC).
   ssl_protocols TLSv1.2 TLSv1.3;

   # Enable TLSv1.3's 0-RTT. Use $ssl_early_data when reverse proxying to
   # prevent replay attacks.
   #
   # @see: https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_early_data
   ssl_early_data on;

   ssl_ciphers 'ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384';
   ssl_prefer_server_ciphers on;
   ssl_session_cache shared:SSL:50m;
   # HSTS (ngx_http_headers_module is required) (15768000 seconds = six months)
   add_header Strict-Transport-Security max-age=15768000;
   # OCSP Stapling ---
   # fetch OCSP records from URL in ssl_certificate and cache them
   ssl_stapling on;
   ssl_stapling_verify on;

   add_header X-Early-Data $tls1_3_early_data;

   location ~ /api/v[0-9]+/(users/)?websocket$ {
       proxy_set_header Upgrade $http_upgrade;
       proxy_set_header Connection "upgrade";
       client_max_body_size 50M;
       proxy_set_header Host $http_host;
       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 $scheme;
       proxy_set_header X-Frame-Options SAMEORIGIN;
       proxy_buffers 256 16k;
       proxy_buffer_size 16k;
       client_body_timeout 60;
       send_timeout 300;
       lingering_timeout 5;
       proxy_connect_timeout 90;
       proxy_send_timeout 300;
       proxy_read_timeout 90s;
       proxy_http_version 1.1;
       proxy_pass http://backend;
   }

   location / {
       client_max_body_size 50M;
       proxy_set_header Connection "";
       proxy_set_header Host $http_host;
       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 $scheme;
       proxy_set_header X-Frame-Options SAMEORIGIN;
       proxy_buffers 256 16k;
       proxy_buffer_size 16k;
       proxy_read_timeout 600s;
       proxy_cache mattermost_cache;
       proxy_cache_revalidate on;
       proxy_cache_min_uses 2;
       proxy_cache_use_stale timeout;
       proxy_cache_lock on;
       proxy_http_version 1.1;
       proxy_pass http://backend;
   }
}

# This block is useful for debugging TLS v1.3. Please feel free to remove this
# and use the `$ssl_early_data` variable exposed by NGINX directly should you
# wish to do so.
map $ssl_early_data $tls1_3_early_data {
  "~." $ssl_early_data;
  default "";
}


my screenshot

Well, you see on your screenshot, that line 1 in your nginx.conf is not allowed.
Which version of nginx did you have installed?

Look at this WebSite for Correct config:
https://docs.mattermost.com/install/config-proxy-nginx.html

best regard