cfnet21
Hi
Off canvas button is using Css from this code
"/tpls/blocks/off-canvas.php" in template "ja_good".
<span class="bar-first"><span class="hidden">bar</span></span>
<span class="bar-mid"><span class="hidden">bar</span></span>
<span class="bar-last"><span class="hidden">bar</span></span>
You can replace it with your image code.