in src/Tools.ts [3:16]
export function openLink(url: string, e?: React.MouseEvent<any>) {
    let target: string | undefined = "_self";   // open in same window by default. This also prevents empty tabs for `mailto:` links in Chrome
    if (window.self !== window.top) {           // CSP (Content Security Policy) can prevent URL changing if we're inside iFrame. We let browser to decide where to open the URL
        target = undefined;
    }
    window.open(url, target);
    if (e) {
        e.preventDefault();
        e.stopPropagation();
    }
}