In general we recommend to choose Krisp microphone from within web-app audio settings. However there are some web-apps which don't expose such setting.
For these cases, you can choose Krisp microphone from Chrome settings. When you do this Krisp will be used with all browser-based apps or services, by default.
Copy the following URL in your Chrome address bar:
chrome://settings/content/microphone
And pick Krisp microphone from the exposed list.
Unfortunately, you cannot choose Krisp speaker in this way.