Although driving a truck can allow independent operators to set their own hours, but the work can be exhausting and the pay low.

driving a truck

hours, but

can be exhausting

No error

The mistake in the sentence is "hours, but"

Explanation:

The subordinating conjunction "although" is introducing a subordinate clause and should be followed by a main clause after the comma.

It is incorrect to place the coordinating conjunction"but" after the comma since it is not linking two independant clauses.

So the correct sentence is the following:

Although driving a truck can allow independent operators to set their own hours, the work can be exhausting and the pay low.

I think it should be " ... hours, the work ... " get rid of the "but."