A Green Card, or Permanent Resident Card, is a document that allows foreign nationals to live and work permanently in the US. Getting an employment-based Green Card can be tricky, however, since it costs money and takes time for your employer to arrange. Improve your chances by first making sure that you are already eligible to apply for a Green Card. Have a conversation with your employer about your desire to get a Green Card, and discuss your options. Work with your employer to make sure you have all the documents you need to apply.
Reference:
https://www.wikihow.com/Ask-Your-Employer-to-Sponsor-a-Green-Card