How can i access other client's network variable? (Netcode for Gameobjects)

for example: How can I achieve to show my current balance in a game, and the enemy player’s balance.
Next to each other.

Disclaimer: I haven’t used netcode, but I haved used mirror, which I believe is similar

As long as the player instance is on both clients, you should be able to get a reference to the script and then access the variable as you would normally. If not, you can try using an RPC to make a function to return the variable.