Deployment/file name Issue

I am attempting to publish via "Import from Git" (using the wizard), a single-page shiny application file named myshinyapp.R. The import runs without error but upon launch of the application I see the error: App dir must contain either app.R or server.R.

I can publish the shiny application with a file name of myshinyapp.R with no issue from desktop RStudio to rstudio connect server (instead of importing from git). Why does importing from git require a specifically named app.R file/is there a fix or change that can be made in writeManifest?

For reference this is what my manifest function looks like:

rsconnect::writeManifest(
     appDir = ".",
     appFiles = c("myshinyapp.R", "report.Rmd", "header.tex", "picture.jpg"),
     appPrimaryDoc = "myshinyapp.R",
     contentCategory = "application"
)