It looks to me that the Power bank module in the image is not a Friting part (probably because they couldn’t find a part) but rather a note in the sketch with wires connected to it, and thus doesn’t reflect what the actual part is supposed to be unless there is a part number somewhere not shown.

It is unclear to me if the 800L I/O pins are 5v tolerant or if you want to use a 3.3V nano to avoid level translation (I didn’t read the data sheet for the 880l that far.) I suspect the power bar module in the image isn’t in fact the USB converter that I posted, but rather an 18650 battery charger / 5V output converter module which needs to be able to provide more than 2A (because the Nano is going to draw current as well) and a step down circuit to get the for the 800l. It expects to connect to a 18650 type LIPO battery (there is a fritzing part for the 18650s) or a 2A capable boost/buck converter adjusted to 4V output to power the 800l. The 800l maximum voltage is 4.2V and giving it 5V may damage it. Ah! This is incorrect in several ways (the article that the converter came from will be worth reading because it describes basically the same setup.) He wanted the 800l as well as the power converter, but the power converter he had is both too low current (the 800l needs 2amps max and the converter is only 600ma) and the wrong voltage.

Fritzing dc power supply