If you want to use ZigZag Exchange on zkSync, you will first need to bridge your funds from Ethereum Layer 1 to zkSync Layer 2. After that, a one-time activation fee is required by zkSync's design to activate your account. You're then ready to start trading on ZigZag.
Go to trade.zigzag.exchange/bridge, switch the zkSync network to the preferred one (mainnet or Rinkeby), connect your wallet and sign the message to access your account
Fill in the amount you want to transfer, click on transfer for ETH or approve+transfer for any ERC-20
If you choose ETH, you can bridge to L2 right away. If you choose any ERC-20, you'll first need to approve the token before being able to transfer
Confirm the transaction in Metamask and wait until your funds are bridged to zkSync