500 internal error in nginx centos

i'm trying to add a captcha in my wordpress login page. i get 500 internal error in firefox console when inspecting the page. i also have this in my nginx error logs:

FastCGI sent in stderr: "PHP message: PHP Warning: Use of undefined constant ‘FS_METHOD’ - assumed '‘FS_METHOD’' (this will throw an Error in a future version of PHP)

these are some parts of my configs:

nginx site config:

server {
listen                               443 ssl http2;
server_name                          example.com;
set                                  $base /var/www/html/mysite;
root                                 $base/public;

# restrict methods
if ($request_method !~ ^(GET|POST|HEAD)$) {
    return '444';
}

# index.php
index index.php;

# index.php fallback
    location / {
            try_files $uri $uri/ /index.php?$args;
    }

# additional config
include /etc/nginx/general.conf;
include /etc/nginx/wordpress.conf;

# handle .php
#location ~ \.php$ {
#    fastcgi_pass unix:/var/run/php/php-fpm/php7.4-fpm.sock;
#    include /etc/nginx/php_fastcgi.conf;
#}

location ~ \.php$ {
#try_files $uri =404;
include /etc/nginx/php_fastcgi.conf;
fastcgi_pass unix:/var/run/php/php-fpm/php7.4-fpm.sock;
#include fastcgi_params;
}

wordpress config:

# WordPress: allow TinyMCE
location = /wp-includes/js/tinymce/wp-tinymce.php {
include /etc/nginx/php_fastcgi.conf;
}

# WordPress: deny wp-content, wp-includes php files
 location ~* ^/(?:wp-content|wp-includes)/.*\.php$ {
  deny all;
 }

# WordPress: deny wp-content/uploads nasty stuff
location ~* ^/wp-content/uploads/.*\.(?:s?html?|php|js|swf)$ {
 deny all;
}

# WordPress: SEO plugin
location ~* ^/wp-content/plugins/wordpress-seo(?:-premium)?/css/main-sitemap\.xsl$ {}

# WordPress: deny wp-content/plugins (except earlier rules)
  location ~ ^/wp-content/plugins {
    deny all;
  }

# WordPress: deny general stuff
  location ~* ^/(?:xmlrpc\.php|wp-links-opml\.php|wp-config\.php|wp-config-sample\.php|readme\.html|license\.txt)$ {
   deny all;
  }

and security config:

# security headers
 add_header X-Frame-Options           "SAMEORIGIN" always;
 add_header X-XSS-Protection          "1; mode=block" always;
 add_header X-Content-Type-Options    "nosniff" always;
 add_header Referrer-Policy           "no-referrer-when-downgrade" always;
 add_header Content-Security-Policy   "default-src 'self' http: https: data: blob: 'unsafe-inline'" always;
 add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

# . files
  location ~ /\.(?!well-known) {
    deny all;
  }

in wp-config.php try to add

define( ‘FS_METHOD’, ‘direct’ )