Connect the D1 mini and its battery shield together. Take care of the pin orientation.
Solder 2 longer red wires to the On/Off switch and put the switch into the base before connecting it into the red wire of the LiPo battery.
On the battery shield solder the 2 sides of the “J2“ solder pad together to enable the battery monitor function used by the code to let you know when the battery gets empty.
After wiring the LED ring to the D1 mini simply plug in the JST connector of the LiPo battery to its power shield connector.