There is no "typical" door. Is it insulated? Is the insulation loose? Does it have an inside skin? What gauge metal is it? Most windows are installed just like you'd expect, by cutting out a rectangle of sheet metal and installing a pre-made special frame for the glass. The installer risks rippling the sheet metal on the cheaper doors (do NOT use snips!), having leaks when done, and most importantly not being able to find the correct frame for the window glass. A garage door company that says it can't do, even with doors with foil-thin metal over foamed-in-place insulation, it is full of it. They do it all the time if they do any customizing work at all, especially if they want to get subdivision contracts.

But they do it in their shop!

Go to Amazon and search "garage door windows". You may get a hit that fits. Consider cutting the hole from the back side with a cheap snag grinder and a thin abrasive cutoff disk. This DOES weaken the top a great deal and a strut/brace may be called for if you don't have one now.

No pro here, but the neighbor just replaced the top panel with a new one that had the windows in it. Looked pretty simple. Removed it from the track. Detached the top row, put on the new row, then put it back in the track. Voila.

He had the ubiquitous 5 row raised panel 16'.

Usually retrofitting windows in a panel hurts the structural integrity of the panel if it was not built with them. There are companies that make panel covers that screw on that look just like windows without the cost of replacing a door or panel.