How do I change the Menu Trigger Layout?

You can change the main Menu Trig­ger Lay­out and Style by going to Appear­ance → Cus­tomize  → Theme options → General. 

For the Menu Trig­ger Lay­out there are three options:

• Icon Only
• Icon + Text
• Text Only

For the options which include an icon, you can choose its Style:

• Three Hor­i­zon­tal Lines
• Plus Sym­bol
• Dots & Hor­i­zon­tal Lines

Fur­ther readings:

• Per­son­al­ize Your Site Appearance