Build an automatic Whatsapp api -- 2

I am selling trough my woocommerce shop an online potty training. What i want is this; If they buy the online course they have to recieve an automatic e-mail. In that e-mail has to be a link. If they click the link there need to be starting an automatic whatsapp conversation. The training is 7 days. So they need to recieve for 7 days long every day an message with an part of the training. If they have questions they can message back. Is it possible to make this and make this automatic?