You could buy a subwoofer with built-in pass-through. To connect it, do DAC->Subwoofer->Amp->Mains.
Alternatively, you could connect both the subwoofer and the Amp to your DAC in parallel.
If your DAC has only RCA output, then use RCA splitters:
View attachment 382794
If your DAC has both RCA and XLR output, then do DAC->RCA->Subwoofer and DAC->XLR->Amp.
The drawback of this method is that you cannot apply a high-pass filter to the JBL A130.
Alternatively, you could buy a DSP like a miniDSP Flex or 2x4HD or DDRC-24.
It connects to the subwoofer and the Amp separately, and you can apply different processing to each output.