How to modify product categories?

[Sinocare_Direct]

My product category is wrong. I am a one fulfillment seller. I opened a case to ask customer service to modify the category. Customer service replied that I can modify it myself. I checked the editor and it is not possible to modify it myself. Can you help me? @w_kiwi 

Current category: Category No. 258788 (wrong)
Correct category: Category No. 258789

[ko_alka]

@Sinocare_Direct What exactly is happening that you can't change the category? Do you get any errors when you go to the listing form?

[Sinocare_Direct]

The Allegro system keeps asking me to link other products, but if I link someone else's product, then my EAN will also change, and it will no longer be my product.

[Sinocare_Direct]

As mentioned in the first picture, I couldn't make any changes.

[ko_alka]

@Sinocare_Direct The offer is not combined with the product. You must link the offer to the product in the Catalog. Do you have an individual EAN code for this product?