For example
Input
PacletInstall["Wolfram/GitLink"]
Output
PacletInstall::notavail: No paclet named Wolfram/GitLink is available for download from any currently enabled paclet sites.
and my PacletSites[] are:
{PacletSiteObject[<|"URL" -> "https://pacletserver.wolfram.com",
"Name" -> "Wolfram Research Paclet Server", "Local" -> False,
"Type" -> "Server"|>],
PacletSiteObject[<|"URL" ->
"https://resources.wolframcloud.com/PacletRepository/pacletsite",
"Name" -> "Wolfram Paclet Repository", "Local" -> False,
"Type" -> "Server"|>]}
