That’s the Search Prime is using as well.
So here is the hook element used to insert it:
https://www.screencast.com/t/dBzo3zDqU
Abd here is the CSS related to the header:
.inside-header {
display: -webkit-box;
display: -ms-flexbox;
display: flex;
-webkit-box-align: center;
-ms-flex-align: center;
align-items: center;
}
.woo-search {
margin-left: 30px;
margin-right: 30px;
-webkit-box-flex: 1;
-ms-flex-positive: 1;
flex-grow: 1;
}
.header-widget {
order: 10;
line-height: 1em;
font-size: 20px;
}
.header-widget p {
margin: 0;
}
Prime is using the header widget to insert the text: GP | Gutenberg | Woo.
Navigation location is set to below header.
Let me know if this helps ๐