Thank you for reaching out! Hope all I swell.
Can you please specify which element did you try to extrude?
The Extrude tool works on lines only (not surfaces or grouped objects).
In general, each element imported into the canvas from the library appears as a ‘Group’. For shapes with lines, you should ‘Ungroup’ the element first so you can select the lines and extrude them.
There are two type of elements in the library:
Native uMake elements - these elements consist of lines and surfaces. As I mentioned above, make sure to ungroup the element so you can select the surfaces or the lines separately.
Non-native elements - these elements were created outside of uMake and consist of surfaces only (no lines). You can apply limited tools on them (array tool, copy, mirror, move/rotate/scale).
Let me know if this answers your question. You can upload a screenshot / video showing what isn’t working for you as well.