Publications required by law to be made in a newspaper or on a statewide website established and maintained as a repository of public notices by a majority of Nebraska newspapers, may be proved by affidavit of any person having knowledge of the fact, specifying the time when and the paper in which or the website whereon the publication was made, and, if made by publication in a newspaper, that such newspaper is a legal newspaper under the statutes of the State of Nebraska, but such affidavit must, for the purposes now contemplated, be made within six months after the last day of publication, in the office where the original affidavit of publication is required to be filed.