BTDT. First step is ensure the wireless keypad is actually capable of working with your opener. I could use the remotes to get the unit going, I couldn't get the wireless keypad to work and I was following the directions. Turned out I was using an older keypad that did not work with that opener. I found a newer one and it has been working fine since.
You can find just about anything in the sears parts link. Look up the opener first by plugging in the model number. Then get the remote model numbers that are listed. Compare those model numbers to the ones on your remotes, and wireless keypad. If they are somewhat close, it should work. If still stuck, look up the model numbers on the actual remote and wireless keypads. You should be able to find pdf manuals on the web without purchasing them. Those manuals will tell you what openers the remotes will work with. That's how I figured out the wireless keypad I was using was not for the opener.