fixed code for getProduct controller model targeted Course instead of Product

controllers/productControllers.js

@@ -379,7 +379,7 @@ exports.getCartDetails = async (req, res) => {
 module.exports.getProduct = (request, response) => {
   let reqParams = request.params.productId;
 
-  Course.findById(reqParams).then(result => response.send(result))
+  Product.findById(reqParams).then(result => response.send(result))
   .catch(error => response.send(error));
 
 }