The error is self-explanatory - budget for a replacement battery soon.

I can't boot the laptop... I'm stuck in the diagnosis menu

How does booting on AC will show what is the problem,  if you mean battery,  how did you came to that conclusion. For example, for me my Dell laptop boots up on AC and with battery inside too, just the battery doesn't charge. In diagnostics it shows battery health 100%, but when I click to diagnose primary battery it gives me the same error code - 2000-0132, which says that battery is reaching the end of its life.

A bad battery can stop a system from booting.  If the system will boot without but not with the battery, the battery is the cause.  If it won't boot either with or without the battery, the cause lies elsewhere.

In your case, run a powercfg /batteryreport (from a command prompt with administrator privileges).  It will generate a report based on how much capacity remains in the battery vs. its design capacity.

Also verify that the system does recognize the AC adapter (f2 at powerup to check).  If the adapter shows unknown, the battery will not charge.  The usual cause is a bad DC plug on the adapter or a bad DC jack in the system.

If the adapter IS detected, but the battery won't charge -- particularly if the capacity is only a fraction (less than 50%) of its design capacity, it's time for a new battery.