DarkRP Modification Addon - Adding Custom Tabs to F4 Menu

Hello!

I’m trying to add a custom tab to the F4 menu in DarkRP that basically allows you to buy a certain group of entities, for example, weapon attachments. I haven’t been able to find much info about doing this, only seen a lot of people posting about how to load webpages through new tabs using the modification addon.

Any help would be appreciated!