How to scale object in AR to its world scale

i am trying to make an AR package in which an object should spawn on default Ar template mesh scale but when i press a button it should change to its world scale .
for that i did add a button to AR template and on click i change the scale value of an object and its working the issue is it change it position .
what is the best way to do it so that it should not change its position when scale .
any heip would be very helpful to me

Set 3d model to center coordinate in 3d software. Model will scale from center and don’t change coordinate. If I understand you correctly.