Deploying online shiny app depending on functions within the R folder (inside a package)

Question

I have an R package called foo that is not uploaded on CRAN but hosted on Github. Within the package, I have, together with standard files and functions within the R/ folder, a shiny app within the inst/ folder. Now, the shiny app use some of the functions of the foo package and I can load the package within the app.R using library(foo) and everything works fine. However when deploying the app online I cannot put foo as dependency and I cannot access the R/ folder (unless I copy the scripts within the inst/app/ folder. Is there a way to deploy an app within a package that use some of the package functions?