Timeline: TypeError when using option loadingScreenTemplate

[annsch]

Hi,
we're using "vis-timeline": "^7.7.3".
When compiling our types we're getting an TypeError when using the options property "loadingScreenTemplate". This property exists and is also used in this example: https://codepen.io/pen. But the property ist not an exported property of node_modules/vis-timeline/types/index.d.ts.
Also the header of these generated types says:

// Type definitions for vis.js 4.21

Could it be that the generated types are based on an older version of the api?
loadingScreenTemplate isn't documented here: https://visjs.github.io/vis-timeline/docs/timeline

Anyways, thanks for your great implementation :)