I am using the react-onedrive-filepicker and the type of file that is returned:

export declare type OneDriveFile = {
    "@microsoft.graph.downloadUrl": string;
    "thumbnails@odata.context": string;
    id: string;
    name: string;
    size: number;
    thumbnails: Thumbnails[];
    webUrl: string;
};

Is there a way to convert this to javascript File?

It can be done through an api: https://docs.microsoft.com/en-us/onedrive/developer/rest-api/api/driveitem_get_content_format?view=odsp-graph-online

But that way I am limited to those Format options provided and also need to use the beta version.