In most cases, Nomad's eSIMs will activate / start automatically when it first connects to the local network.
Install your eSIM before your flight, and turn on your eSIM when you arrive at your destination. Your Nomad eSIM will activate automatically when it connects to the local network. Activation before you arrive at the destination is not possible.
In some cases, you might need to manually activate your eSIM - please refer to the email containing the installation instructions for more details. In these cases, you can activate your plan when you are ready to use data either by clicking the "Activate Now" button on the website or Nomad app.
If you need to access the Nomad website/app to activate data, you will need a stable connection, so please consider doing it before arriving at your destination.