How can I add the SV language to the tag language selector?

@singshi90 : First you will have to add a language (if not already available, you need to specify the language code and locale etc for eg:- sv_SE) to Edit tag Dialog.
In CRXDE, edit the multi-value property languages of the node /content/cq:tags.

Please refer the documentation here: https://experienceleague.adobe.com/docs/experience-manager-65/content/implementing/developing/platform/tagging/building.html?lang=en#adding-a-new-language-to-the-edit-tag-dialog

After, you have added the language, it will start appearing in the Tag Editor dialog now and you can specify the Localized tag value for that language. Please refer AEM documentation: https://experienceleague.adobe.com/docs/experience-manager-65/content/sites/administering/contentmanagement/tags.html?lang=en#managing-tags-in-different-languages

Some of the already accepted references: https://stackoverflow.com/questions/77045781/how-to-add-new-languages-to-aem-tags-for-localisation

thanks.