I'm very sorry for that, I've set the region restriction to Europe according to https://www.steamgifts.com/discussion/6L3NB/humble-bundle-july-2023-humble-choice-44-the-outer-worlds-back-in-stock
but now I have searched the comments and some people report even shorter list of countries where this can be redeemed in. Can I ask which region you are in? Maybe it is in Europe filter on Steamgifts but not on this shorter list:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IM IS IT JE LI LT LU LV MT NL NO PL PT RO SE SI SK

Again apologies, Humble did not show me any region lock, and this game is apparently very restricted :(

I've answered the same also on Steam chat.