Hi Support,
Welcome to the Microsoft Q&A forum.
Based on your description, you would like to recover data from a group chat that has ended.
For this request, this cannot normally be done by a regular user. You will need to contact your tenant administrator, typically your IT department, to check whether the content can be searched for and retrieved using Microsoft Purview eDiscovery.
You can provide your administrator with the following documentation:
Finding content in Microsoft Teams in eDiscovery | Microsoft Learn [f6da-e2fd-f46-3ddc]

If your administrator is still unable to find the content from the Teams group chat you are looking for, I recommend asking your administrator to open a support ticket with Microsoft Support. The support team can investigate the issue further and determine whether the content you need can still be retrieved.
To create a support ticket with Microsoft Support, you can refer to the following documentation:
Get support - Microsoft 365 admin | Microsoft Learn
I hope this information is helpful.
If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.
I look forward to continuing the conversation.
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