I am trying to build a pipeline for RNAseq data analysis in nextflow. Please, I have not been able to get the first step which is to download the SRA files. Please do you have any suggestions for the following error?

This is the code:

#!/usr/bin/env nextflow

srr_ch = Channel.from( lista.txt)
srr_ch.println()


 process fastqdump {
   container 'quay.io/biocontainers/parallel-fastq-dump:0.6.5--py_0'

   input:
   each srr from srr_ch

   output:
   file("*.fastq") into fastq_ch

   """
   prefetch ${srr} && parallel-fastq-dump -t 8 -s ${srr}
   """
   }

This is the error:

N E X T F L O W  ~  version 22.06.1-edge
Launching `null` [elated_hodgkin] DSL1 - revision: c897000175
No such variable: lista

 -- Check script 'script1.nf' at line: 3 or see '.nextflow.log' file for more details