Hi,
The PIR datasheet will tell you.
The PIR sensor will only draw as much current as specified in the datasheet.
The supply needs to be able to deliver this current. Usually there should be some headroom.
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Maybe you have a LED lamp that is specified to draw 20mA form a 12V supply.
It will draw 20mA from a small 12V power supply rated with 100mA.
It will draw 20mA from a big 12V battery rated with 200A.
But to use a supply rated with less than 20mA won't work.
Klaus