Add the code below to Custom CSS field on your Chat widget’s Appearance tab:
.global-styles,
[class*="FloatingButton__FloatingButtonContainer-sc"] {
top: 0;
bottom: auto;
margin-top: 10px;
}
.global-styles,
[class*="Window__WindowComponent-sc"] {
bottom: auto;
top: 0;
margin-bottom: 0;
margin-top: 96px;
}