You can add custom textured tooltips for your items, please refer to this example addon:
https://www.spigotmc.org/resources/items-custom-tooltip-texture-example-itemsadder-addon.87883/
{% hint style="warning" %}
- you cannot show custom enchants as they will go out of the window if the image is too small
- you have to write everything in the tooltip image, text would go out of the window if the image is too small {% endhint %}