Caution is advised here. The author principally has the exclusive right to put the work online and must give their consent. However, a newspaper can be digitised and put online without the author’s consent if the copyrights in the newspaper have expired. This is the case if the original author, the editor of the newspaper, has been dead for more than 70 years. It does not matter from a copyright perspective whether the publisher as a legal person has been assigned the copyrights by the author or has become the author’s legal successor through inheritance. Even if the newspaper has not appeared for more than 50 years, you may not know whether the editor has been deceased for more than 70 years. Therefore, you should advise the library not to copy the newspaper and put it online.