The deadline for filing a lawsuit challenging a will is three years from the date you learned about the existence of this will. Now the statute of limitations has expired. It can be renewed, but for this there must be good reasons that prevented you from contesting the will in court 20 years ago - and there must be evidence of these reasons in the form of documents. The court will not renew the term for contesting the will without valid reasons and supporting evidence. If there are no valid reasons, there is no point in going to court.