I am using enrichr to perform some enrichment analyses. In their documentation they say that you can indicate the background list, or simply a number of genes for the background:

background (int) – BioMart dataset name for retrieving background gene information. This argument only works when gene_sets input is a gmt file or python dict. You could also specify a number by yourself, e.g. total expressed genes number. In this case, you will skip retrieving background infos from biomart.

source: https://gseapy.readthedocs.io/en/latest/run.html?highlight=background#gseapy.enrichr

1. Is it possible to provide this background as human gene symbols? If so, how?
2. May I provide the background myself? I want to have a smaller set of genes as background.
3. I'm unable to provide the size for the background as well, and even though I have background=700, I still get ValueError: backgroud should be set or int object

thanks in advance