@fragolinux OK, I couldn't see why it didn't start... but after manually running the command I see this...
pi@raspberrypi:~ $ cd ~/Blynk && java -jar BlynkServer.jar &
pi@raspberrypi:~ $ -bash: line 13: java: command not found
And I suspect what happened (I will have to dig through the script to be sure) is similar to installing Blynk client on my old RPi Model B v2.0... I think the current, AKA "easy" way, of installing Java doesn't work, due to older processor or something? (EDIT - nope... that was a NodeJS issue, not Java) My existing LS is installed on a Netbook running Mint, so I never had to run into this issue before.
Hmm... re-ran the script to look for errors and found these...
aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for Raspbian/stretch
Package oracle-java8-installer is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'oracle-java8-installer' has no installation candidate
Oh well, guess I will have to figure out the alternate way to install Java on this flakey old pi.