I finally got it to run the server
but there is a warning and I do not know how to proceed with it.
pi@raspberrypi:~/Blynk $ java -jar server-0.26.2.jar -dataFolder /home/pi/Blynk Java HotSpot(TM) Client VM warning: You have loaded library /tmp/libnetty-transport-native-epoll8349522589992915587.so which might have disabled stack guard. The VM will try to fix the stack guard now.
It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'.