After Greencard

Hello to you all I have been reading experience on this forum and it has helped me a lot during this stressful time waiting, I filed form I-175 on 5/8/19 got transferred on 2/20/20 from Vermont to Patomac , on 9/11/20 status updated to we certified the approval of your formI-751 and send it to appropriate appellate office this office will send you a final decision, I don’t understand because I have never seen this before so anyone can tell me what this means, are they going to mail the green card or it’s not finished processing and to all those waiting with the same timeline or close hope this gives you some hope that you will hear something soon