E-Commerce GDPR Compliance

In setting up our E-Commerce site and allowing users to create an account, I have noticed that there is no option for us to have users accept our terms of service as users are creating the account. GDPR does not allow us to collect PII on users in the EU without their consent. How can I add a radio button that forces users to accept our terms of service before when we collect their billing address, phone number, etc.? Without this ability, Infusionsoft’s E-Commerce Platform is not compliant with GDPR.

Although, I can’t give legal advice, I would take a look at 1(b) of “Performance of a contract” and the GDPR Readiness guide that also covers the topic: https://www.infusionsoft.com/legal/gdpr-readiness-guide#lawfulness-of-processing