If you’d like to display the stream (i.e custom pixels) in LVGL you can use the canvas widget. In SquareLine Studio you can’t create one directly, but if you want to design a certain layout/size for it graphically, first you can create a container/panel with given size as a placeholder, and replace it by a canvas widget in the exported ui-code.
But alternatively, it’s even better not disturbing the exported code, but creating a SCREEN_LOADED event for the screen on which the panel/container you created (with ‘Don’t export fuction ticked’ if you’d like it to be external), and then create the canvas in the assigned function of the exported code (ui_events.c if you set the function to be exported).
You can create the canvas as a child of the panel/container widget. In case you want the canvas to determine the dimensions, the container/panel had to be set to size ‘content’ in SquareLine Studio before the export.)
For further usage of the canvas see its LVGL page: Canvas (lv_canvas) — LVGL documentation