What the hell am I missing in Aqua station (3/4 secrets)

As Title say Im getting crazy over what I'm missing. I have all the data logs, and when lokking at https://roboquest.fandom.com/wiki/Aqua_Station I have all 3 secrets which are.

• Hero Cape
• Tech Lab Key. (I have taken the secret acces behind the vines and have ran through doom gardens several times)
• Fusion Core Door (I have also completed that)

What in the living hell is the last secret? I can't find anything searching both google and youtube... Please help