Thank you for your answer.
Maybe I understood wrong, you are right I am currently not paying in greenstock, but I had understood that by downloading the gsap-member.zip and then installing via npm gsap-bonus.tgz (as stated in this video https://vimeo.com/391314787) the files will be uploaded in the node_modules folder.
When I run install gsap and install gsap-bonus.tgz this is my log:
Thank you, once again, maybe I got it wrong!