I have enabled envelopes, now each time i open LO the envelopes format appears. How can i disable it

I open Libre office to write a letter but when the window opens i get the envelope template, please advise me how to close the envelope template.

As this is a Writer question the tag should be writer. Open Writer, click File > New > Templates... (Ctrl+Shift+N), in the dialog that opens scroll down to Default (or another template you want as default), right-click it and select Set as default. Now Writer will always open with a blank page (or the other template that you selected). Cheers, Al