LED display duck tongue advertising cap

There are three button controllers in the cap, which are A, B, and c.
Stupe
A key: long press boot
1
A KEY: LONG PRESS BOOT.
C key: Shift key, display sets 9 gear positions. M1-M7 is a fixed display content, M8-
Stupe
M9 is the editing gear.
C KEY: THE SHIFT KEY, DISPLAY SETTING NINE GEAR. M1 - M7 TO FIXED DISPL AY CONTENT, M8 -M9
FOR EDITING THE GEARS.
When you select the editing gear, press C again to enter the editing mode. In this mode: A key is ↓
Stupe
Select the B button for selection. Appear in the display
...
Blank,
<←" for deletion
3

After editing, press and hold the C button again, and play your own DIY in the display.