Resize partition with Gparted

I need to resize my sda4 to be able to install a program that needs quite much GB. I booted to my USB stick and tried Gparted but I couldn't make it to work resizing. I have an unallocated space of 3 GB I tried to use also with no luck. How to use this unallocated space for sda4? Or any other solution? I need at least 2 GB more.

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