You can generate a password fairly easily. Unfortunately you will not be able to send the generated password via email to the user. It is not best practices to be sending passwords in emails, and Sailpoint has made a point of not storing passwords in logs or emails.
If you are able to set the Password via a Create API call, then you may be able to reset the password via an API too. If you have ISC Password Manager licenses, you could add an HTTP Operation for Change Password. You can create the account with a random password that no one knows, then have the user go to Password Manager and set the password.
To setup a generated password:
In the Account Management section of configuration, create a mapping for Password in Create Account. Select Generator, and choose Generate Password.
In your HTTP Operations: Create Account, add
"password": "$plan.password"to the body JSON.