To upload the Custom Product Builder plugin to your magento store you should:
1) download it from git.buildateam.io, and then open a command line, where you should write the direction for your magento folder and ‘setup:upgrade’ and click enter
2) After the process finished write the second command: ‘deploy:mode:set production’ ,click enter and wait till the end of compilation.
3) After it successfully ended you should go to the admin panel of your magento store , enter the login and password, and you will come to the main page.
4) There you should go to ‘stores’ on the left menu (1), and click on ‘configuration’ button in the settings menu (2)
5) Make sure that Product Builder is installed successfully, you will see it in that page
You can also see the video instructions for installing The Custom Product Builder plugin for your magento store: