It is possible in UGENE opening text data and files by pasting them into the Project View from the clipboard.

Select text data in a browser or in a text editor or file(s) from your system and press Ctrl+C (Cmd+C for macOS).

Switch to UGENE with an opened project, click the project area and press Ctrl+V (Cmd+V).

The copied data or file(s) will be opened in UGENE.

 Another way for the file(s) is drag-drop. Using your mouse, drag and drop the files from the file system to UGENE, and they will be opened by the program.