If the personal data of your voters is stored at POLYAS, then yes.
You can find the data processing agreement along with our Terms and Conditions, and you can download it here: https://www.polyas.com/terms-and-conditions.
SaaS customers who have registered themselves in the configurator and not through a POLYAS employee agree to the terms and conditions when they sign up. The data processing agreement is attached to the terms and conditions under https://www.polyas.com/terms-and-conditions. By agreeing to the terms and conditions, the data processing agreement is concluded without the need for a signature. The procedure was drafted and approved by our lawyers.
If you as the election organizer operate the electoral roll yourself, or if SecureLink authentication is carried out using an anonymized ID, then the answer is no.