Demo endpoint - https://mobile.x-cart.com/admin.php?target=graphql_api
You can either go straight to https://xcart.github.io/graphql-api-docs/ or use any GraphiQL-client, e.g. ChromeiQL (https://chrome.google.com/webstore/detail/chromeiql/fkkiamalmpiidkljmicmjfbieiclmeij)
Replace the schema.graphql file to change GraphQL Api schema definition file (you can create it by using get-graphql-schema tool.
You must have Ruby and bundler gem in order to render documentation website. Run the following cli commands to generate documentation:
bundle install
bundle exec rake
After that, simply commit and push them to the repo.