Can I receive OTP codes while using a travel eSIM?

SMS one-time codes are sent to your phone number, which lives on your home SIM — not on the data-only travel eSIM. Keep your home SIM in the phone and connected so it can receive texts; you can leave its data roaming off to avoid charges, since incoming SMS is usually free. App-based codes (authenticator apps, push notifications) work over the eSIM's data.