The Green Keycard is a low-level clearance door key. You can find security doors requiring a green card at almost all points of interest.
Often, the green keycard security door is the first you must enter to complete a point of interest puzzle.
You can collect a green keycard from several points of interest. Namely, Oxum’s, Abandoned Supermarkets, Lighthouse and Junkyard.
You can also find green keycards on almost all NPC scientists. Roaming scientists will sometimes be carrying one, but the Cargo Ship and Tunnel Scientist counterparts will be holding one nearly half the time.
Before you can use any keycards, you will need to collect a few fuses.
The locked doors at points of interest do not have power, with each card reader is attached to a fuse box, usually a short distance away from the door itself.
Once you insert an Electric Fuse into the fusebox, you will have a limited amount of time to make it to the door and swipe the keycard.
Each keycard has a limited amount of uses and will decrease its overall health each time you swipe it through a card reader.
Alternatively, you can sell any unwanted green keycards to the Bandit Camp Shopkeeper for 15 Scrap pieces if you have no interest in running the monuments.
For more information, check out our guide on green keycard locations: