To fetch sequences from the local BLAST+ database use the Fetch sequences from local BLAST+ database->Fetch sequences by 'id' from 'blast result' context menu item of the blast result. The following dialog will appear:
Here you need to select a query ID, database, type of file(s) and output path. After that click on the Fetch button. To fetch sequences for several annotations at the same time select the blast results with Ctrl key and call the Fetch sequences from local BLAST database->Fetch sequences by 'id' from 'blast result' context menu item.