What is FlexXTEND?
The FlexXTEND panel in Adobe Premiere is a plugin that allows the editors to browse, search, preview and use media from the Flex system in their Premiere projects compositions and save said compositions back to Flex. More advanced capabilities include the upload of local media to the Flex system and saving Adobe Projects to Flex for ongoing work. The FlexXTEND panel is run from Adobe Premiere and is an extension of the Flex system.
For the back-end, read the article: FlexXTEND Installation and Configuration
For the front-end, read the article: FlexXTEND User Guide