Extrude along Bezier ( path )

How can I make a circle or a cube extrude along a curve which bends along different axis ? Something like a pipeline, but sold. Thanks.

I use v 2.82a

I am stuck here

According to a video to create pipes, I need to pick Object under Bevel. But when clicking on the circle, it does not get selected at all.

Another video said Object > Apply > Rotation and Scale for the circle , then

Object > Convert to > Curve from Mesh/Text for the same circle. Now when I click the Object through Bevel, I am able to select the circle. But the extrusion is like a huge pillar or a big distorted sphere. The circle has no extrusion along the path.

This video helped : https://youtu.be/31rhH3FM9-c

I had to select the circle which I used for Bevel and use the Edit Mode. In my case, I scaled down the circle in the edit mode and had to rotate around different axis to get the sought way of extrusion along the path.

Self note - Both object should be a curve
If you get a distorted extrusion, manipulate the base object in Edit Mode.

Let me add that if you set the curve’s vertices to vector you get a square. Next time don’t write a post every time you want to add some info, just edit the original one.