how to purchase RH442 course via training units

[Wei_Xiong]

hello team 

can somebody teach me how to purchase RH442 course via training units? i got below steps, but can't find "Add to cart" button on the course page Red Hat Performance Tuning: Linux in Physical, Virtual, and Cloud (RH442)

thank you very much in advance

PFA course or locate a course or exam on their website

1. click “Add to Cart” and “Checkout” if you are done shopping.
2. Login to your Red Hat account
3. During step 3 of the checkout process (Payment Method), enter your Training Unit Agreement

Best Regards