To load a q script it needs to be loaded from the local disk.
You could also use .Q.hg to download the file directly into your process with either of the following as examples:
q)"rn" vs .Q.hg `:https://raw.githubusercontent.com/KxSystems/kdb/master/sp.q
/or
q)ssr[;"rn";""] .Q.hg `:https://raw.githubusercontent.com/KxSystems/kdb/master/sp.q
However with this approach you’d need a lot of customization per code block to execute it locally.
If you are downloading the script to the local q process, why would you not store it on disk anyway? For example, re-loading later instead of multiple downloads.