Hi @Leigh Galas-Espino ,
Thanks for posting in the community. For your question, my suggestion is to create a new Assest library to save the flv file.
If you are using SharePoint online, you will need to do the following to add an Assest Library:
- Site Settings->Site Collection Features-> active Video and Rich Media (Classic) features.
2) Site Content->new App-> Type Assest Library, if you don't find it, click on classic experience, then find Assest Library again.
3) If you are using Sharepoint Server, you can find the Assest Library directly in the Site Contents.
4) After creating the Assest Library, you can refer to this link to upload your flv files: Upload video, audio, or pictures to an Asset Library - Microsoft Support
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