To check the IFSC code in the SBI YONO app, start by logging in with your credentials. Once logged in, navigate to the account section where you can view details of your bank account. The IFSC code is usually displayed along with other account information. Alternatively, you can find the IFSC code on the cheque book or passbook issued by the State Bank of India. If you're unable to locate it within the app, you can also visit the official SBI website or contact customer service for assistance.