We’ve identified the root cause of this issue. The currently public exported npm package is webview v3.3.17, which does not include the injectedJavaScriptBeforeContentLoaded API - that feature was introduced in v3.5.x, which hasn’t been released to customers yet.
Requesting you to please wait for the next release (v0.23) , which is expected soon.
Thank you for identifying this issue and helping us make Vega better.
Warm regards,
Ivy