Ask HN: EUPL question

1. Say there's a fancy new service released under EUPL which adds two numbers

2. I create a website which prompts the user to enter two numbers

3. The entered numbers are dispatched to the the service in #1 for addition

4. I return the result to the user

Under EUPL, am I required to release the source code of the website which collects the two numbers, makes the call to the service, and returns the result?