4WD hat adding LEDs

Good evening, I am trying to add LED lights to the 4WD car. I need to connect to GPIO18, 10, 12, or 21, unfortunately when looking at the hat I do not see them labeled nor is there documentation for a diagram of which pin corresponds from pi to hat. This is for a school project, if anyone could help with this dilemma. I appreciate your time and thank you in advance!

Right. d1 is the GPIO18 pin.
Give you the 4wd-hat wiring schematic for you to check.

That looks like is was drawn by you so thank you for taking the time to do that I appreciate it! What Im looking for is if im running a python script on my raspberry pi 3b+ and I have to use one of those four aforementioned pins, I need to know which are which on the hat itself ( see picture circled yellow area) I should probably add that im not using the pico version, sorry about the confusion!

I was able to figure it out is the digital sig pin 1, thank you for your help!

If you need to add LEDs that need to be connected to GPIO 18, 10, 12 or 21 pins, you can find the pins you need to connect by looking at the 4WD hat wiring schematic we have provided. Please see the schematic.
And click on this link: