I'm going to assume that you meant where can I find a Nintendo Switch in stock?
It is pretty rough right now in terms of finding a switch console for sale online. The shortage has been caused by various different factors, but the current health crisis mixed with the release of animal crossing new horizons (and switch reselling/buying bots), switch consoles have run dry.
There was a report not too long ago that stated that Nintendo plans to raise output of systems this year, but I think no one really knows quite when that will happen. (It is also unlikely that will be anytime in the near future).
There's always the option of ebay or similar sites, but with the crazy high price inflations there, I would stay away. People are scalping the heck out of switch consoles there. One other option though is the Switch Lite. While the Switch Lite doesn't connect to a tv or come with a dock, it still is able to play most of the games that the original Switch can play too.
The Nintendo Switch Lite is still available at various different locations. You can actually even buy a Switch Lite from the official Nintendo Store (as of the time of my writing this) for $199.99:
https://www.nintendo.com/switch/lite/.
So for now, it seems the best options are to either just wait it out until the stock is refilled of the normal base model of the Nintendo Switch or buy a Nintendo Switch Lite. Hope this helps!