Needs will give points to who gives out an honest answer

The correct answer is the last option - Add to Document.

When you choose to add the envelope to the document it adds the envelope as the first page of the document. When printing you can either print it as part of the document, or customize your printing to only print the envelope or the letter individually.

the only way i would see could be an autoclicker type software. but that is very time consuming.

i'm so sorry that's not a question and this isn't an answer