I write a smart contract name SauravToken in which i created ERC20 tokens for sale. After that i want to create a token sale web application . for the token sale web application i try to load the smart contract in App.js file Here is the code

App.contracts.SauravToken.deployed().then(function(instance){
                sauravTokenInstance = instance;
                return sauravTokenInstance.TokenPrice();
                }).then(function(TokenPrice){
                App.TokenPrice = TokenPrice;
                $('.token-price').html(App.TokenPrice.toNumber());
            });

But the localhost:3002 show the Uncaught TypeError: Cannot read properties of undefined (reading 'deployed')

the deployed() function should return the contract instance, but it is not. Please help.