SuperTokens is an open source authentication solution offering features like: Different types of login: Email / password, Passwordless (OTP or Magic link based).

SuperTokens.com

Hello, I would like to be able to save additional user information during account creation using passwordless recipe. Can you tell me how I can get to this behavior?

So when is the info collected? When the user is typing in their email?

After receiving the OTP by SMS, I think the user creation happens when the code is confirmed and the account doesn't exist, that's when I would like to add additional user information before generating the new user.

right. So the user would enter some additional info along with the OTP?

We do have docs on how you can do something after a user is created in supertokens: https://supertokens.com/docs/passwordless/common-customizations/handling-signinup-success#2-on-the-backend

Yes, for example his name. If I send these additional fields in the OTP confirmation request, can I get these fields in this overwrite?

yes. You have access to the request object using `input.options.req` using which you can read the body containing the extra info