Thank you for your help.
We want to do like this:
1. Add icon “.freshio-icon-grip-horizontal” with text “分类” in the second place of icon button on the mobile bottom; https://prntscr.com/zv47nx https://prntscr.com/zv4ach
*** When click the icon, will display a popup menu on the left (about 50% of width),
to show the product categories menu with sub categories: https://prntscr.com/zv4o4p