In order to make it work, gh-pages must be enabled, go to settings, click on "pages section" and once in pages section, look for Branch then leave it as the immage below.

gitbook-cli

$ npm install -g gitbook-cli

1. Clone the project

2. Once in the project folder there will be 2 languages folders, en and es, each one with a README.md (it will be the first page the user will see after choosing the language) file.
   Also there will be other .md files, those are the pages that will be shown in the website. If Want to add a new chapter, a new .md file must be created, finally for it to appear on the site it must be added to SUMMARY.md

3. The new changes can be tested using the following command $ npm gitbook build followed by $ npm gitbook serve

4. If eveything is ok, the changes can be pushed to the remote repository using the following commands:

$ cp -R _book/* .
$ git clean -fx _book
$ git add .
$ git commit -m "commit"
$ git push origin main