However, I recommend buying some parts from their original suppliers; they are cheaper and are directly associated with the footprints: 

Note: I am still trying to figure out the battery situation, it looks like the digikey part placed on the board is designed to work with protected 18650s, so purchase one on Amazon that has a button.

If you are looking to order the BoM from Amazon, here are some untested options. Look out for an update if somebody builds it successfully. LM2596 Buck Module Battery Holder UNTESTED FIT Locking Switch 18650 Battery Red 0805 LEDs 100pcs Rainbow LEDs! 100pcs M3 Screw Kit

The original design also uses USB-C to power the sign. See that reference if you are interested in alternative power options.

Managing power with a mechanical switch isn't ideal. In the /markwuflux/q4-2022-dogfooding-on-air-markwu2001-remix-r1, I used the enable pin of the power supply to ramp up power to the LEDs in a more controlled manner.

If we were to use the SSZYY0805R for our LEDs (which can be purchased on LCSC), we can see that the LED has a nominal 2.0V forward voltage and draws 10mA under that condition.

In our application, we have 99 LEDs total so the total current we would ideally draw is 990mA @ 2.0V. When tracing the connections between LEDs, make sure that the trace widths can handle that much current by using a PCB trace width calculator.

To determine how much power we need to supply, we need to count how many LEDs there are.

Go to the PCB view (the button is located at the top of the app) and click on the object panel on the left. You can expand through the Letter Modules until you see the component count. Because the terminals count as components, just subtract 2 from the number you see for each letter. Write these numbers down somewhere.

Welcome! Please click through these bubble comments to learn about the design!

Search for any letter in the alphabet in our universal parts library in the left panel!

These LED+Silk modules follow the naming convention: "Letter [X] Module"