Add the code below to Custom CSS field on your widget’s Settings tab:
.global-styles, [class^="Icon__IconContainer-sc"] {
width: 93% !important;
height: 93% !important;
top: 55%;
left: 56.5%;
}
.global-styles, [class^="PopupCloseControl__PopupCloseControlContainer-sc"] {
width: 25px;
height: 25px;
}
You’re welcome to change the values in the code to adjust the button to your liking.