Can't install trainer.

[shynkevich-alex]

LOGS:

fastlane add_plugin trainer [✔] 🚀 [14:48:58]: fastlane detected a Gemfile in the current directory [14:48:58]: however it seems like you don't use bundle exec`
[14:48:58]: to launch fastlane faster, please use
[14:48:58]:
[14:48:58]: $ bundle exec fastlane add_plugin trainer
[14:48:58]:
[14:48:58]: Get started using a Gemfile for fastlane https://docs.fastlane.tools/getting-started/ios/setup/#use-a-gemfile
+-------------------------+---------+---------+
| Used plugins |
+-------------------------+---------+---------+
| Plugin | Version | Action |
+-------------------------+---------+---------+
| fastlane-plugin-trainer | 0.4.1 | trainer |
+-------------------------+---------+---------+

[14:49:00]: Make sure to commit your Gemfile, Gemfile.lock and Pluginfile to version control
Installing plugin dependencies...

Your user account isn't allowed to install to the system RubyGems.
You can cancel this installation and run:

  bundle install --path vendor/bundle

to install the gems into ./vendor/bundle/, or you can enter your password
and install the bundled gems to RubyGems using sudo.

Password:

Your user account isn't allowed to install to the system RubyGems.
You can cancel this installation and run:

  bundle install --path vendor/bundle

to install the gems into ./vendor/bundle/, or you can enter your password
and install the bundled gems to RubyGems using sudo.

Password:
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

current directory:
/private/var/folders/4q/5xhgmkwj5ysgwjl7dw09nn740000gn/T/bundler20191011-86603-1qbmauajson-2.2.0/gems/json-2.2.0/ext/json/ext/generator
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby -r ./siteconf20191011-86603-1elvwhw.rb extconf.rb
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /var/folders/4q/5xhgmkwj5ysgwjl7dw09nn740000gn/T/bundler20191011-86603-1qbmauajson-2.2.0/gems/json-2.2.0 for inspection.
Results logged to
/var/folders/4q/5xhgmkwj5ysgwjl7dw09nn740000gn/T/bundler20191011-86603-1qbmauajson-2.2.0/extensions/universal-darwin-18/2.3.0/json-2.2.0/gem_make.out

An error occurred while installing json (2.2.0), and Bundler cannot continue.
Make sure that gem install json -v '2.2.0' --source 'https://rubygems.org/' succeeds before bundling.

In Gemfile:
fastlane-plugin-trainer was resolved to 0.4.1, which depends on
trainer was resolved to 0.9.1, which depends on
fastlane was resolved to 2.133.0, which depends on
json`