In reply to Paige Miller.

As you wish, Paige Miller! I've updated the macro in the Github repo to accept four keyword parameters: proxyhost=, proxyport=,proxyusername=, and proxypassword=.
Download and compile the macro code again just as you did before. Calling %listrepofiles(?) will now include syntax help for the new parameters. Let me know if it works for you or not.
NOTE: *LISTREPOFILES Documentation *******************************

SYNTAX:
%LISTREPOFILES(user,repo)

Required parameters: (Case sensitive!)
user = Username for repo owner
repo = Repo name

Optional parameters:
branch = branch (default: master)
extension = file extension (default: all files)
proxyhost = Proxy server host name (default: option not used)
proxyport = Proxy server port number (default: option not used)
proxyusername = Your proxy server user name (default: option not used)
proxypassword = Your proxy server password (default: option not used)

Examples:
Retrieve a list of all files in the master branch of the
SASJedi repo named sas-macros:
%LISTREPOFILES(SASJedi,sas-macros)

Retrieve a list of SAS files in the master branch of the
SASJedi repo named sas-macros:
%LISTREPOFILES(SASJedi,sas-macros,,sas)

Proxy-related parameters are keyword parameters. For example,
to retrieve a list of all files in the master branch of the
SASJedi repo named sas-macros using a proxy server:
%LISTREPOFILES(SASJedi,sas-macros,proxyhost=myhost.example.com,proxyport=898)

*************************************************************
May the SAS be with you!
Mark