Hello good Morning.
I'm trying to install an application that needs Ruby on Rails on a server with CPanel. When I exec:

bundle install

I get this error:

Installing nokogiri 1.10.10 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /home/x7x90umvk5hl/rubyvenv/redmine/2.6/gems/nokogiri-1.10.10/ext/nokogiri
/opt/alt/ruby26/bin/ruby -I /opt/alt/ruby26/lib64/ruby/2.6.0 -r ./siteconf20200903-1782984-j0wf21.rb extconf.rb
mkmf.rb can't find header files for ruby at /opt/alt/ruby26/lib64/ruby/include/ruby.h

You might have to install separate package for the ruby development
environment, ruby-dev or ruby-devel for example.

extconf failed, exit code 1

Gem files will remain installed in /home/x7x90umvk5hl/rubyvenv/redmine/2.6/gems/nokogiri-1.10.10 for inspection.
Results logged to /home/x7x90umvk5hl/rubyvenv/redmine/2.6/extensions/x86_64-linux/2.6.0/nokogiri-1.10.10/gem_make.out

An error occurred while installing nokogiri (1.10.10), and Bundler cannot continue.
Make sure that `gem install nokogiri -v '1.10.10' --source 'https://rubygems.org/'` succeeds before bundling.

In Gemfile:
  rails was resolved to 5.2.4.2, which depends on
    actioncable was resolved to 5.2.4.2, which depends on
      actionpack was resolved to 5.2.4.2, which depends on
        actionview was resolved to 5.2.4.2, which depends on
          rails-dom-testing was resolved to 2.0.3, which depends on
            nokogiri

Can you help me?

Thanks in advance