variable=count(integer) in a Character Blueprint.
I want to increment the variable when user presses the 'R' key.
What do I so in the Blueprint that variable remains the synchronized between the server & client?
In server- 'R' key pressed 3 times so count value should be 3.
In client-'R' key pressed 4 times, so then the value should be 7.
If I'm understanding you correctly, you have a variable and you only want it to increment once when the client presses the R key but what's happening is it is being incremented on both the server and client, doubling up the count.
To get around this, you need to use the Switch Authority node
Make sure the variable is replicated and only allow it to be incremented by the server.