"fromSources" with typescript only accept string array, how to add a custom source?

[Jerome]

I'm using typescript, but the 'fromSources' definition is the following

` /**

• Valid sources are:
• • local_file_system - Default
• • url - Default
• • imagesearch - Default
• • facebook - Default
• • instagram - Default
• • googledrive - Default
• • dropbox - Default
• • webcam - Uses device menu on mobile. Not currently supported in Safari and IE.
• • video - Uses device menu on mobile. Not currently supported in Safari and IE.
• • audio - Uses device menu on mobile. Not currently supported in Safari and IE.
• • box
• • github
• • gmail
• • googlephotos
• • onedrive
• • onedriveforbusiness
• • customsource - Configure this in your Filestack Dev Portal.
• • unsplash
    */
    fromSources?: string[];`

How can I put a custom source, that is defined as an object?

Expected Behavior

Provide a Typescript type for the 'custom source' and update 'fromSources' to accept both string and this new type.

Current Behavior

Only string accepted, i can't put my custom source with Typescript

Possible Solution

Steps to Reproduce (for bugs)

I try to use the exemple in the Filestack tutorial for custom source, with Typescript

Additional Screenshots

Context

Your Environment

• Version used: 3.25.0
• Browser Name and version: any
• Operating System and version (desktop or mobile): any
• Link to your project:
• Typescript

-- EDIT --
When I force the type to "string" with "myCustomSource as unknown as string" it's working.
But, it's clearly a workaround, waiting to the "fromSources" type to be enhanced.