[Plugin: ZdMultiLang] Zdmultilang & slidingdoor theme

I am using Zdmultilang plug-in and it works well so far. the only problem is that I am using the wordpress theme ‘slidingdoor’ and the hyperlinks on the sliding images should be changed from https://classic.sp-yachts.com/?cat=8 to https://classic.sp-yachts.com/?cat=8&lang=en as much as it does on the sidebar.

Could you help me writing the write word on the header.php to make it select the right category and the right lang?

thanks veru much for your support

https://www.ads-software.com/extend/plugins/zdmultilang/