REST API returns different dimension and resolution from export directly from the figma client

when i export the icon manually in figma, it return the 72 * 72 size and 108* 108 dimension (1.5x png) but when i use the images api with scale= 1.5, it return the 108 * 108 size and 72*72 dimension, and even i change the scale, the dimension won’t change, can we fix the api?