RStudio does not "see" or connect to https://www.shinyapps.io/

Hello, mysteriously, my RStudio no longer shows me the option to deploy documents to https://www.shinyapps.io/, although it shows me connections to rpubs.com and to Rstudio Connect. I've read through various help forums and am unable to connect to shinyapps, despite trying this on two different machines. Any suggestions would be appreciated.