First, look carefully for the code. Activation codes are written on a small piece of paper located within the insert in the back of the book. These can be easy to miss. Double check all around in case it was misplaced. If you still cannot find it, you will have to contact Pearson at this link to request another one.
My 10% discount code for CompTIA vouchers doesn’t work.
If the disc (or the book for that matter) was damaged before it got to you, contact the seller, be it Amazon, Barnes & Noble, etc… They have a responsibility to replace it. (Likewise if an activation code is missing or the insert in the back of the book was opened or damaged.)
Thankfully, in 2017 Pearson decided to go “diskless” meaning that optical discs would not be included with books anymore. (I was lobbying for that for years…)
Now, extra materials are stored on companion web pages on http://www.pearsonitcertification.com