Unable to deploy Shiny app with Gurobi content

Hello,
I've written a shiny app that uses Gurobi's API to optimize data based on user inputs. The app runs fine locally in RStudio, but I'm running into trouble deploying it on account of Gurobi. The Gurobi package is only available when you sign up for a trial copy of Gurobi. I placed the zipped package in a sub-folder with my app and data files and added the following line to my app:

options("repos" = c("CRAN" = "https://cran.rstudio.com", "custom" = "gurobi/"))

Nevertheless, I get the following messages when I try to deploy:

Warning: unable to access index for repository /gurobi/src/contrib:
scheme not supported in URL '/gurobi/src/contrib/PACKAGES'
Warning: unable to access index for repository /gurobi/src/contrib:
scheme not supported in URL '/gurobi/src/contrib/PACKAGES'
Warning in FUN(X[[i]], ...) :
Unable to find repository URL for package gurobi

Thank you in advance for any help you can provide! I'm relatively new to R and don't have a strong programming background.