In order to collect payment in your survey for upgrades, shipping fees, and any extras purchased, you will need to connect your Stripe account for credit card payments.
Under the Settings menu item, there is a sub-menu item for Payments, which will allow you to connect your Stripe and PayPal accounts. Stripe is required for projects located in countries in which it's available. PayPal is optional, and some backers really appreciate having it available. If you are not in a country where Stripe is available, consider Stripe Atlas, a service whereby Stripe will set up you up with an LLC corporation in the US, as well as a US bank account, and a Stripe account.
If you've added a Stripe and/or PayPal account on a previous project, you can import those accounts to the new project.