Open a web browser on your device, such as Google Chrome, Mozilla Firefox, or Microsoft Edge.

Type the URL for HDHub4U (https://hdhub4u.com/ or similar) in the address bar and press Enter.

On the streaming page, you may see ads or pop-ups. Be cautious when interacting with these ads, as they may lead to malware or other security risks. If you're able to bypass the ads, you should be able to stream Iron Man 3.

Click on the movie link to access the streaming page for Iron Man 3.