You have to be very explicit and clear about what you data you are handing over in GDPR and how it will be used. Making an account usually does not have that in

You have to be very explicit and clear about what you data you are handing over in GDPR and how it will be used. Making an account usually does not have that information. Additionally, you need to give a person an option to not hand over that data and still use your app/site 'without detriment' unless that data was essential to your tool.