The latest available information says there are no active codes for War Base Tycoon right now.

If you meant War Tycoon instead, these codes are currently listed as working: ONEBILLION , WAR1MIL , BlueTweet , Boom , Wiki200K , New Map! , bug spray , Fireworks24 , Mega , and Half Mil.

Working codes for War Tycoon

Code| Reward
---|---
ONEBILLION| Neon Nightfall skin, 1M cash, 3 Elite Cases, 15 medals 6
WAR1MIL| 1 Research Instant Unlock, 1 Elite Camo Case, 1,000,000 cash, 10 medals 6
BlueTweet| Sapphire skin 6
Boom| Verdant gun skin 6
Wiki200K| Magmaflow gun skin 6
New Map!| 15 medals, 250k cash, 30 min 2x cash boost 3
bug spray| 25 medals 3
Fireworks24| 5 limited skins, requires over 1 rebirth 3
Mega| Mystic gun skin, 100k cash, 10 medals 7
Half Mil| 55 medals, 550k cash 7

To redeem codes in War Tycoon, open Roblox, launch the game, click the gear icon, choose Codes , enter the code, and press Redeem.

TL;DR: War Base Tycoon currently has no working codes listed, while War Tycoon does have several active codes.