This is the base code for using SVG in the header
<svg xmlns="http://www.w3.org/2000/svg" style="display: none;">
<symbol id="gb1" viewBox="0 0 180 160" > /*set viewBox to match SVG*/
/* place each icons SVG code here */
</symbol>
<symbol id="gb2" viewBox="0 0 180 160" > /*set viewBox to match SVG*/
/* place each icons SVG code here */
</symbol>
<symbol id="gb3" viewBox="0 0 180 160" > /*set viewBox to match SVG*/
/* place each icons SVG code here */
</symbol>
<symbol id="gb4" viewBox="0 0 180 160" > /*set viewBox to match SVG*/
/* place each icons SVG code here */
</symbol>
</svg>