Okta Signin Widget not available for Vue 3/VueCLI 4

I am attempting to integrate the okta signin widget into a Vue 3 project, based on the following: (Okta Sign-In Widget and Vue | Okta Developer). However, it appears that OktaSignIn is not available to import into the config files even after installing via yarn add @okta/okta-signin-widget. In other words, I cannot add import OktaSignIn from '@okta/okta-signin-widget' to the main.ts, as the package does not appear to be available. Is this widget not yet available for Vue 3 or Vue CLI 4 ?