function register(address _recipient) public onlyUnregistered returns (uint256 tokenId) {
    address smartContract = msg.sender;

    if (_recipient == address(0)) revert InvalidRecipient();

    tokenId = _tokenIdTracker.current();
    _mint(_recipient, tokenId);
    _tokenIdTracker.increment();

    emit Register(smartContract, _recipient, tokenId);

    feeRecipient[smartContract] = NftData({
        tokenId: tokenId,
        registered: true
    });
}
// Check that the receiver account  exists in the evm store
if acct := k.evmKeeper.GetAccount(ctx, event.Recipient); acct == nil {
  return sdkerrors.Wrapf(ErrNonexistentAcct, "EventHandler::RegisterEvent account does not exist: %s", event.Recipient)
}
