Why does it download a file when trying to go to phpmyadmin?

Question

PHP

Installed Nginx, I want to install phpmyadmin. During installation, in the window where you need to select a server, I do not select anything, I click "OK", in /etc/nginx/sites-available/default like this:

server {
  listen 80 default_server;
  listen [::]:80 default_server;

  root /var/www/html;

  index index.php index.html index.htm index.nginx-debian.html;

  server_name _;
  
  location / {
    try_files $uri $uri/ =404;
  }
  location /phpmyadmin {
               root /usr/share/;
               index index.php index.html index.htm;
               location ~ ^/phpmyadmin/(.+\.php)$ {
                       try_files $uri =404;
                       root /usr/share/;
                       fastcgi_pass unix:/var/run/php/php7.4-fpm.sock;
                       fastcgi_index index.php;
                       fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                       include /etc/nginx/fastcgi_params;
               }
               location ~* ^/phpmyadmin/(.+\.(jpg|jpeg|gif|css|png|js|ico|html|xml|txt))$ {
                       root /usr/share/;
               }
        }
        location /phpMyAdmin {
               rewrite ^/* /phpmyadmin last;
        }
  #location ~ \.php$ {
  #	include snippets/fastcgi-php.conf;
  
    # With php-fpm (or other unix sockets):
  #	fastcgi_pass unix:/var/run/php/php7.4-fpm.sock;
    # With php-cgi (or other tcp sockets):
  #	fastcgi_pass 127.0.0.1:9000;
  #}
}

When I go to /localhost/phpmyadmin
Just downloads the file.

How to fix this matter?