The information you will need to add in Step #3 depends on your location (country). Usually you will be asked to add the following:
For the US, Stripe requires the last 4 digits of SSN to be provided.
For Canada, Stripe requires SIN to be provided.
For Hong Kong, Stripe requires HKID to be provided.
For Singapore, Stripe requires NRIC or FIN to be provided.
For other countries (Australia, New Zealand, Japan, Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom), Stripe requires the scan of ID document to be provided.
These are the usual minimum requirements. Sometimes you will be required to add additional information, but that's not typical in the early stages of working!