Instead of 12V/2A Power Adapter How to give power to GSM module real time usage

Hai sir,

we have a custom board(for iot product) ....in that we are using GSM sim900A....till now we used 12V/2A power adapter to give power to my board for testing purpose...but,in real time scenario which one i should use for my custom board to give 12V/2A exactly???

can you please give any solution??

thankyou in advance :)

The manufacturer of the custom board can tell you what power sources to us.