Hi, I'm new in Arduino stuff (
I dont know how to connect an Arduino MKR GSM 1400 to a battery. Can you help me?
And I don't know how this relates to a problem with the IDE 
Hence moved to a more suitable location on the forum.
No experience with your board so can't answer the question.
With a USB powerbank?
Follow Arduino recommendation by using supported battery "Li-Po Single Cell, 3.7V, 2500mAh minimum with Battery connector JST PH". Check https://docs.arduino.cc/hardware/mkr-gsm-1400