Slow downloads and the best usage for downloading data via Nemo portal

I am downloading fastq files from the nemo data portal using the ‘portal_client’ tool via:
portal_client -m nemomanifest.tsv
This downloading method is quite slow.
I notice the URLs in the manifest are from a google cloud platform (beginning with gs://) and am curious whether specifying the downloads as being from a google bucket will speed things up.
The portal_client requires specifying a google-client-secrets file (.json) and google-project-id specification for downloading google cloud storage buckets.
Is there a place where I can download the client-secrets file?
Any guidance as to speeding up downloads would be a huge help, thanks!