How to add tutorial project to github pages

I completed step by step tutorial.

Than I’d like to try to develop this prof-of-concept to my personal page on github.

Googling I found this page:

Side note: I am not able to find where is this page linked from, but this is not the problem

I added github-pages to plugins

group :jekyll_plugins do
  gem "jekyll-feed", "~> 0.9"
  gem 'jekyll-sitemap'
  gem 'jekyll-seo-tag'
  gem "github-pages"

Then executed bundle update, but I got this error

mirko@DESKTOP-3QBL88J MINGW64 /f/Progetti/myblog
$ bundle update
Fetching gem metadata from
Fetching gem metadata from
Resolving dependencies...
Bundler could not find compatible versions for gem "jekyll":
  In Gemfile:
    github-pages x64-mingw32 was resolved to 4, which depends on
      jekyll (= 1.1.2) x64-mingw32

    minima (~> 2.0) x64-mingw32 was resolved to 2.5.0, which depends on
      jekyll-feed (~> 0.9) x64-mingw32 was resolved to 0.11.0, which depends on
        jekyll (~> 3.3) x64-mingw32

Kindly, can you say me what am I doing wrong?

I’m using Windows 10 Pro and git bash, as you can see; just if it matters

There’s are a couple of things you can do.

Firstly, the github-pages gem already bundles a fixed set of gems (see this list). So, remove duplicate gems from your Gemfile and try again.

If that doesn’t work, simply delete your Gemfile.lock and run bundle install once again.

If that too doesn’t work, perhaps you’re using an outdated version of Bundler.
Update if your version is lower than v1.16 and try again.

If issues still remain, please post the full contents of your Gemfile