Closing a position in part

Dear Dan,
Can you please explain to me how to exit in part a position? I’m currently using the platform on IPad.
I tried through the button LIQUIDATE but is only possible to close a position completely.
Thanks & Regards.

On live account or paper trading?

Paper account. Also I’m testing other platform; can you please be so kind to confirm if ODD LOTS MIXED LOTS AND ROUND LOT rules are valid in this platform too?
This platform has great execution and less slippage on breakout. And it’s magic if you want to exit with 3-4-5 portion for commissions reasons, if it is possible
Thank you&Regards.