Hello,
By default, you can set the header row into 1 or 3 columns using the settings of the Header Builder as listed in our theme documentation here: https://xtemos.com/docs-topic/header-rows-and-columns-configuration/
But if you would like to set it in 4 columns, you can achieve it with a trick, set the Row into 1 column: https://postimg.cc/75SKstvq and then use the HTML block into it: https://postimg.cc/tsdzt1PT
Note: You can create the new HTML block and then set any content in it with any number of columns as per your requirements then you can set it to your header.
Best Regards,