Cutadapt output for paired end data

I am dealing with RNA seq paired end data in a list. After running cutadapt, the outputs are the forward strand and reverse strand in two seperate lists. Now I want to use RNA STAR to map the trimmed sequence to the genome, but the input categories don’t have forward and reverse strands in two different lists. What should I do? Is there anyway to move the inside the list to the outside? Or can I merge the two lists together? Thanks!