[galaxy-user] Galaxy on Cloud not recognizing .txt files as fastq

Hello, I have been able to get Galaxy to instantiate on our Cloud account, and would like to use the NGS tools to trim and map Illumina libraries. However, when I tried to import .txt files (the data contained in these files are in fastq format) located in an S3 bucket, Galaxy did not recognize them as fastq data. I tried to import the files via the URL of the S3 bucket, and Galaxy just imported the actual name of the URL rather than the file itself. Do I need to change the extension of these .txt files to .fastq? Or have I gotten something wrong with respect to the location of the data in the S3 bucket? thanks for any help! karl