WN3000RP range extender -- connecting to FIOS Actiontec MI424WR

So here is a very simple question.
* I set my FIOS router to WEP Security
* Reset the WR3000RP to factory and log into the mywifiext.net
The setup has 4 SIMPLE steps ONLY
1) Select existing network -- i can do that
2) Apply Security -- very simple

2a) I enter the passphrase a 64 bits same as on my router
2b) There are 4 empty boxels for "Key 1, Key 2, Key 3, Key 4". What goes there? Where do I get the Keys?
If I presse the "GENERATE" button, it populates the 4 keys with codes.

But I think this may be my problem????
When I go to the next steps

3) Configure Extender: I check the "use same passphrase"
4) Finalize setting -- no problem.
Then I switch the WiFi connection to the new mySSID_ext. But The WR3000RP does not connect to the FIOS Router.

Somewhere in Step # 2 above I think the KEY1 through Key 4 are wrong....

How do I find what these Keys are?

Thanks.