Obviously you want this:
In the left there's some black shapes drawn as seen straight to downwards when flying above the shapes. The shapes are paths and path-like basic curves such as circles and rectangles. Raster images do not work nor groups, but paths and path-like curves which do not overlap (see NOTE1) can be combined with Path > Combine.
In the right path effect Perspective Envelope is added and the corners are dragged with the node tool to the wanted perspective.
The shapes can be made free and editable without losing the perspective by applying Path > Object to Path and Path > Break apart.
Path effect can be copied and pasted to another path. Simply copy an effected path to the clipboard, select another path and apply Path > paste path Effect.
NOTE1: Actually also overlapping paths can be combined, but if there's fill colors, they can get unified, vanish or there can appear to be holes. Everything can be fixed after the enveloping by applying Path > Object to Path and Path > Break Apart. An example:
There's an ellipse and a blue rectangle. Fill color vanished with Path > Combine. The coloring was taken from the ellipse. After inserting Perspective envelope and making the parts free again all colors were re-inserted manually.