I am using free 7-days trial. Currently have 3200 credits but cannot generate a video. All the time prompting for money to add. already paid once already around $8. Still have no ability to generate. Please help. Sincerely, Mila

Hey ​@Colorful_Aurora1daa 
Help us. Help you. 
Sorry to hear you're running into this issue. Could you provide more information; so, the team can proceed to troubleshoot? Without the requested information it is difficult to assist you and resolve the issue. 

A Full Screenshot or short video:  Please provide a screenshot of your entire browser or application window, including your avatar in the upper right corner. Many errors have multiple causes; seeing the full context is much more helpful than a zoomed-in image of the error message alone.
>>Make sure to remove person details: email address, name... before posting<<

• System Details: Specify your Operating System (OS) and Browser (including version numbers).
• Workflow Context:
  • Which Firefly function were you using? (e.g., Text to Image, Generative Fill, Text to Video, etc.)
  • Which model was selected? (e.g., Firefly Image 3, Image 4 Ultra, Imagen 3).
  • The full prompt you were using.
  • Copies of any reference images, keyframes, or original images used.

Other suggestions

1. Try a different web browser (or an Incognito/Private window) to rule out browser extensions or cache issues.
2. Disable any active VPN, ad-blockers, or strict firewall settings temporarily.
3. Clear your browser's cache and cookies (see image below):

 For more details and additional troubleshooting steps, you also check this article as well!

Suggestions on How to Prompt
https://community.adobe.com/questions%2D404/use%2Dadobe%2Dfirefly%2Dto%2Dgenerate%2Dyour%2Dimages%2Dand%2Dvideos%2D1476088?tid=1476088&fid=404
Cheers

Nate