There are two options that I can think of,
1. The latest chart widgets provided by AtlasUI, has auto-refresh property, works well in 7.13.1 not sure about 7.10.0. But I would suggest upgrading to latest modeler version if possible. Refer link below.
https://atlas.mendix.com/p/widget_linechart/5910974510925681
2. With the ChartJS widget you don't get to refresh it atleast for now, so you would have to use MF timer widget from Appstore - https://appstore.home.mendix.com/link/app/105695/ to set interval to call your WS MF repeatedly.
I would suggest you check out the AtlasUI way. Good Luck!