Well, I tried all what I could but I really can't, I don't know much about json and all of that.
I have the ItemCostCalculator:GUIShop.json file but what do I do next? I read another post asking the same question and it has an answer but I don't know what it means, if someone could help me step by step with the ItemCostCalculator:GUIShop.json file I would be so glad.
Thank you for reading  and I hope I can get a fix :)

Replace the contents of 'ItemCostCalculator_GUIShop.json' to '"Shop - Shop Categories":' options in GUIShop's config...

How can I do that?
I tried like, copy paste but all that does is that the config generates another 8 thousand lines with the names again in english and with the default prices :c

Merged post

Could you give me like, a video explaining how to do that please? Thank you 

Use this site to edit json.   --> http://jsoneditoronline.org/#/
I suggest you learn the json format.
If the config is reset automatically, your config is formatted incorrectly. Use this site to check json format--> https://jsonlint.com/

I tried using it but I really can't understand why it doesn't work. I'm sorry if I'm annoying you, but I really want to be able to configure this.
I'll leave you the pastebin with my GUIShop json config.

https://pastebin.com/89h8RnHU

As you can see there, I pasted the ICC_Config json file where the Item IDs go, and then the plugin generated all again but in english. Thank you for reading.