If you want to take the opposite direction for each trade copied, you can set Reverse Trades to yes.
Copy From is the Lead account and Send To is the Follower account.
When using risk multiplier by balance the trade copier will consider the balance of the Copy From and Send To accounts to calculate a proportional lot size for each copied trade.
The math used to calculate the Send To lot size:
The multiplier value can be used to adjust the lot size further. A Multiplier of 2 will double the Send To lot size. Conversely, a Multiplier of 0.5 will halve the Send To lot size.
Risk multiplier by equity works in the same way as risk multiplier by balance but uses the equity values of the Copy From and Send To accounts, instead of the balance.
The math used to calculate the Send To lot size:
When using lot multiplier the lot size is calculated by taking the Copy From lot size and multiplying it by the Multiplier value.
When using fixed lot all trades taken by the Copy From will be copied to the Send To at the defined Fixed Lot value. It does not matter how big or small the Copy From lot size is, it will always be the defined Fixed Lot value.
The slippage setting is used to protect against large variations in spread/price between the Copy From account and Send To account. For example, setting your slippage to 20 means the Send To account will only copy a trade if the Send To account price is within 20 pips on the positive side of the Copy From account's open price.
If the price never gets back within the Slippage setting the trade will not be copied in the lifetime of the Copy From account trade.
The Slippage value used is up to you to decide based on your own preference. The lower the value set the higher the chance that some trades will never be copied as the conditions are never met. You can even set a negative Slippage value, which would mean only trades in a drawdown will be copied.
The Max Lot setting can be used to protect in scenarios where the Copy From account takes an abnormally large trade. As the current risk settings will always be applied, regardless of the lot size being attempted, the Send To account attempt could attempt any lot size that the broker will accept. To combat this, you should set a reasonable Max Lot value as the largest lot size you are prepared to open on the Send To account.
The Force Min Lot setting can be relevant if you are using Risk Multiplier and the Send To account has a relatively small balance compared to the Copy From account. Some brokers have a minimum lot size of 0.10 lots on symbols, compared to the more common 0.01 lots.
By choosing to Force Min Lot you could be exposing the Send To account to larger than expected trades. Conversely, if you choose to not Force Min Lot you can potentially miss trades as the attempted lot size is below the broker-defined minimum lot size.
Please consider what scenarios could happen before choosing to Force Min Lot.