Hard to find....maybe you can get the carburetor part number for a google search? Otherwise a new carb popped up on Amazon pretty reasonable. I went that route for an old B&S motor years ago.
Get the model, type and code off of the OHV valve cover opposite of the one with the fuel pump hose connected to it, and then you can go to several websites and look up the exact Briggs parts from there. Or post it here and I can look them up with Briggs dealer site.