Refseq annotation files are available for many genomes from NCBI. See: https://www.ncbi.nlm.nih.gov/refseq/
There are other sources depending on the organism/genome build version. Try UCSC, Ensembl, and the like. Before using with tools, make sure that the reference genome that the annotation is based on is an exact match for the reference genome in use. This includes ensuring that the chromosome identifiers are in the same format.
Best, Jen, Galaxy team