paired end (as collection)

I upload SRR15324080 data in plants.usegalaxy.eu. I am using Trimmomatic flexible read trimming tool for Illumina NGS data tool.

the data is paired end sequencing (merged in one file). So, I select paired end (as collection) in the tool but I do not see the name of my data in Select FASTQ dataset collection with R1/R2 pair.
How can I set the default for this sample? Can anyone help me?