you can't.
http://www.bba-reman.com/content.aspx?content=Test_for_Renault_Key_Immobiliser_failures_emergency_recode
bought a second hand card key for laguna 2001 to reprogramme the key for my car what do i do
How do I re program my key fob for renault laguna estate 1997?
8 mm square key
KEFON
Insert your key in the ignition. Turn it to accessories. Press your remote lock button until you hear a beep. Now it's configured!
Weak battery Loose or corroded battery cables
You can ask to a Renault dealer. They have acces to Renault database and can give you these code free of charges!
If your Renault Laguna's key card is broken, you can lock the vehicle manually using the physical key, which is usually hidden inside the key card. To access it, slide the release button on the key card to extract the metal key. Use this key to lock the driver's side door. Alternatively, you can use the vehicle's central locking system from inside to secure all doors.
See the link for further info on how to fix
To reset the alarm on a Renault Laguna, first, ensure the vehicle is unlocked using the key fob or the key itself. Then, insert the key into the ignition and turn it to the "On" position without starting the engine. After a few seconds, turn the key back to the "Off" position and remove it. This should reset the alarm system. If the issue persists, consult the vehicle's manual or a professional for further assistance.
If your Renault Laguna won't start with the key card despite the radio and door locks functioning, it may indicate a problem with the key card itself, such as a dead battery or a faulty transponder chip. Additionally, there could be an issue with the vehicle's immobilizer system, preventing it from recognizing the key card. Try using a spare key card if available, and if the problem persists, consult a professional mechanic or a Renault dealership for further diagnosis.