PageSpeed Insights: Image elements have no explicit width and height

Dear support, Checking Page Speed with PageSpeed Insights I get the recoommendation to set an explicit width and height for image elements to reduce layout offsets and improve CLS for images displayed in the header: div#main-wrapper > div#header-featured-image > and images displayed via Featured Contend Do you have a solution for that? Thanks for any ideas on this Ulrich for: https://www.stiftung-meeresschutz.org/