you have to add font-family to your app
follow these steps (https://docs.mendix.com/appstore/modules/document-generation/)
Download the font Noto Sans SC.
Copy the font file NotoSansSC-Regular.ttf from the static folder of the downloaded font package into the theme\web\fonts folder of the app.
In Studio Pro, go to Styling > Web > main.scss in App Explorer, and add the lines below to the main.scss file in the built-in styling editor:
font-family: 'Noto Sans SC';
font-family: 'Noto Sans SC', sans-serif;
Add the class font-noto-sans-sc to all applicable text and widgets.