If you have an eSIM compatible device and you get an error message that your device is “locked” exclusively for another provider when trying to install an eSIM profile on it, then it will first need to be “unlocked”.
When a device is locked, it means that you can only use a SIM card/eSIM profile from the carrier from which you bought your device. To unlock it, you just need to contact that carrier and request the device to be “unlocked” (you just need to provide its IMEI that you can find under the settings).
After that, your device will be unlocked automatically, and you will be able to use any SIM card and any eSIM profile on it.
NB : Please note that some devices are equipped with an eSIM, but you will not be able to use it, whether your device is locked or unlocked, as this eSIM feature can be restricted for some markets/countries. In this case, we advise you to contact the device manufacturer for more information.