PR application approved but no visa stamped in passport yet

[MrsLew]

When my stepson go his biometrics done in a Jamaica was advised by the vac center that he will receive an email when it is time to go back and hand in his passport but he hasn’t received that email yet and today my husband received an email saying that both his and his sons PR application was approved and want us to reply back to the email with some information to get an invitation to create a portal account to submit a photo and stuff but where I am confused is that it wants an estimated time as to when my stepson will arrive in Canada (husband is already here on work visa) but we don’t know that information as he hasn’t received an email to get the visa stamped in his passport…please help me understand this