Battery charging indicator light on a MacBook Air 13inch?

The MacBook Air with the M1 chip comes with a USB-C charge cable and there is no charging indicator light.

The MacBook Air with the M2 chip comes with a MagSafe 3 charging cable and there is a charging indictor light on the MagSafe 3 end of the cable.

Mac OS X has a battery icon in the upper right corner of the menubar. When there is a lightning bolt over this icon, it indicates it is charging. You'll also get a Power Source readout when you select that icon in the menubar, so you know if it is battery or power adapter.

Keep in mind the one USB-C power machines need a pass through USB-C hub to add charge to external peripherals that don't have their own source of power. Getting a hub with its own AC adapter is usually better, because then you can add your own USB-C devices. Here are two that use the USB-C charger for power:

https://www.smklink.com/products/usb-c-multi-port-hub

https://www.siig.com/catalogsearch/result/?q=JU-DK0F11-S1

Magsafe 3 is now coming back to most of the MacBook line. That will bring back some of the charging indicators on the cable. Even on Magsafe 2 this wasn't always a 100% reliable indicator. There are a lot of knockoff cables where the LED doesn't work, or gives you an inaccurate indication. I tend to depend on the software indicator.