[Vlasenko Fedor]

Попробуйте так

server {

    server_name funprograms.ru;
    root /var/www/api;
    index index.html;
    listen (:):443 ssl; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/funprograms.ru/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/funprograms.ru/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
    add_header Strict-Transport-Security "max-age=31536000" always; # managed by Certbot
    ssl_stapling on; # managed by Certbot
    ssl_stapling_verify on; # managed by Certbot

  location / {
    client_max_body_size 100m;
    client_body_timeout 600s;
    client_body_in_file_only clean;
    client_body_buffer_size 16K;
    proxy_connect_timeout      70;
    proxy_send_timeout         90;
    proxy_read_timeout         90;
    proxy_redirect off;
    proxy_set_header host $host;
    proxy_set_header X-real-ip $remote_addr;
    proxy_set_header X-forward-for $proxy_add_x_forwarded_for;
    proxy_pass http://localhost:5000;
  }
}