Custom onboarding flow

Hello, I need to set an onboarding flow for my user that resume in 5 steps

1- collecting user data

2- collecting user' business data

3- showin registring confirmation

4- sendind a ling to users mail in order to have him creat his password

5- Validate password rules the redirect user to his dashboard.

but the plate form do not allow any customisation of onboarding flow.

can somebody help me out on this one ?