Many users prefer using Chrome specifically for captchas because Google's reCaptcha often works more smoothly in its own browser.
After setup, you can literally browse normally – JDownloader silently catches links in the background. jdownloader set browser
If not auto-detected, go to extension settings and manually set: Many users prefer using Chrome specifically for captchas
For a more seamless experience, you can install the browser extension. This allows you to send links directly from your browser's right-click context menu to your running JDownloader instance. jdownloader set browser