It's true. See this from Congress.gov

[Wiz Imp]

https://www.congress.gov/crs-product/R45920

Members may add or remove their names until a petition has obtained 218 signatures. If a discharge petition reaches this threshold—a majority of the House's 435 Members—the list of names is frozen, printed in the Congressional Record, and the discharge motion is entered in the House Journal and in the "Calendar of Motions to Discharge Committees" section of the House Calendar. Once on the Calendar, an additional seven legislative days must elapse before a Member who signed the petition may notify the House in a floor statement of an intention to offer the discharge motion on the floor. The motion may then be called up by that Member "at a time or place, designated by the Speaker, in the legislative schedule within two legislative days after the day on which a Member whose signature appears thereon announces to the House an intention to offer the motion."5 A discharge motion is not in order, however, during the last six days of a congressional session.