partitioning – Retrieve free space into my main partition on my new cloned installation

I used clonezilla to clone my current ubuntu installation on a new SSD drive.

It worked fine, but i noticed my free space is still the same (The old SSD was a 120gb one and the new one is a 240Gb)

on the KDE partition manager i noticed i have unallocated space, and i would like to be able to retrieve that unallocated space on my current work partition.

How can i do this? i have an idea but i would like to ask before i do any changes on this.

Thank you in advance.enter image description here