Data-only means internet, not a new phone number
If a plan is sold as data-only, use it for apps, maps, email, messaging services and internet calling. Do not assume it includes ordinary carrier voice or SMS unless the plan explicitly says so.
Your home number can often stay active
On a dual-SIM-capable phone, you can usually keep your normal SIM or eSIM enabled for calls and texts while the travel eSIM handles mobile data. Your carrier may still charge for roaming voice or SMS activity on the home line.
Apps such as WhatsApp use data
Messaging and calling apps can continue to work over the travel eSIM's internet connection. They are separate from carrier SMS and do not require the travel eSIM to have its own phone number.
If receiving bank codes or carrier SMS is important, plan around your home line. A data-only travel eSIM should not be treated as a replacement phone number.