According to the Preview download page...
According to the latest
url...
# effective_url is just: curl -s -I -w '%{url_effective}\n' -L $1 -o /dev/null
Ubuntu ~ $ _effective_url https://rstudio.org/download/latest/preview/desktop/bionic/rstudio-latest-amd64.deb
https://s3.amazonaws.com/rstudio-ide-build/desktop/bionic/amd64/rstudio-1.3.1073-amd64.deb
# To make sure curl didn't get it wrong...
Ubuntu ~ $ wget https://rstudio.org/download/latest/preview/desktop/bionic/rstudio-latest-amd64.deb
--2020-08-18 12:48:14-- https://rstudio.org/download/latest/preview/desktop/bionic/rstudio-latest-amd64.deb
Resolving rstudio.org (rstudio.org)... 45.33.2.142
Connecting to rstudio.org (rstudio.org)|45.33.2.142|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://s3.amazonaws.com/rstudio-ide-build/desktop/bionic/amd64/rstudio-1.3.1073-amd64.deb [following]
--2020-08-18 12:48:14-- https://s3.amazonaws.com/rstudio-ide-build/desktop/bionic/amd64/rstudio-1.3.1073-amd64.deb
Resolving s3.amazonaws.com (s3.amazonaws.com)... 52.216.10.173
Connecting to s3.amazonaws.com (s3.amazonaws.com)|52.216.10.173|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 126783260 (121M) [application/x-debian-package]
Saving to: ‘rstudio-latest-amd64.deb’
rstudio-latest-amd64.deb 100%[========================================================================>] 120.91M 13.7MB/s in 9.2s
2020-08-18 12:48:24 (13.1 MB/s) - ‘rstudio-latest-amd64.deb’ saved [126783260/126783260]