Automatically liking Affiliate Record with Affilate Product

Hello again,
The issue I have (and others as well, I believe) is that by using the aff_signup.php, the system creates a record in the database but does not send a mail to the Affiliate, confirming User Name and Password.

I have spent several more hours last night to read through the various posts in this Forum and I now understand that I need to create a product for Affiliates.

I have done that. When linking - MANUALLY - the new record (created via the aff_signup.php) with the Affiliates Product, the system generates the email confirmation.

However, I do not yet see how I can AUTOMATE the linking of the Affiliate product with the Affiliate record. Having to do this manually each time is not a viable solution.

Is it a question of coding the aff_signup.php template?

Please advise. Thank you. Kind regards, Doris