The action “Course Grant Offer” will add access to the contact for a course offer/product.
Keep in mind this will only send an email with login details if you have the template enabled in Course > Email Settings. Otherwise, you would use an additional workflow with the Course New Signup trigger for unique to course login detail emails. Please see our other articles on courses for assistance with this.
Please Note: Login details will only send the first time an offer is granted to a contact.