Custom image not working

Hello

This addon is easy to use so i guess I didn’t miss any steps. I don’t know why my custom image button isn’t working. I’s ok when I use a default image but not with the one I’ve uploaded.

– I’ve selected “use custom image”
– Then I selected my file (I either tried png and jpeg)
– In the media library I click “show” on the image i want
– then “insert into post”

But nothing happens. Is it something i do wrong ? Or what could be the issue ?
Thanks In advance for your help

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