Btw none of the things are centered because of frame bounds try this :3
frame = `{\\"isLinked\\":false,\\"pathDataList\\":[],\\"fillImageBounds\\":{\\"minX\\":-${Math.floor(imgWidth/2)}.0,\\"maxX\\":${Math.ceil(imgWidth/2)}.0,\\"minY\\":-${Math.floor(imgHeight/2)}.0,\\"maxY\\":${Math.ceil(imgHeight/2)}.0},\\"fillPng\\":\\"${b64PNG}\\"}`