iOS makes eSIMs almost invisible — once you know which three screens matter.
Install
On iPhone, tap "Install eSIM" in the Roambee web app or the email with your QR code. iOS opens Settings and adds a new line. Label it "Travel" so it is easy to spot.
Set the right defaults
Settings → Mobile Data: set Mobile Data to the Travel line and keep your main line as Default Voice Line. Turn off "Allow Mobile Data Switching" to avoid accidental roaming on your home SIM.
Data Roaming
Settings → Mobile Data → Travel → Data Roaming: On. This is the single most common reason for "No Service" — it must be on for the travel line.
If it still won’t connect
Toggle Airplane Mode once, or select the network manually under Network Selection. Still stuck? Chat with support — it works over Wi-Fi.