Undeployed App: Failed to install 'shinysky' from GitHub.

I published Shiny App. Status is Undeployed. When I open the app, it raises an error:

An error has occurred

The application failed to start: exited unexpectedly with code 1

Loading required package: devtools
Loading required package: usethis
Downloading GitHub repo AnalytixWare/ShinySky@HEAD
Warning in i.p(...) :
'lib = "/opt/R/4.0.5/lib/R/library"' is not writable
Error in value[3L] : Failed to install 'shinysky' from GitHub:
unable to install packages
Calls: local ... tryCatch -> tryCatchList -> tryCatchOne ->
Execution halted