Hello, Cristina,
Thank you for the screenshot, however, it is missing a description. Would you like to add a search feature to the header content on mobile? To do this, please go to the Header Builder > Mobile > add the Search element, as shown in the example here: https://prnt.sc/4JsR9SEDfj9A
If you have any additional questions or concerns, please do not hesitate to reach out to us. Our support team is always available to assist you.
Kind Regards,
8theme team