You need a UserBase account before you can be added to the Translator group, register or log in here adding your details to the bottom of the list. If you haven't already done so, consider adding your email address on your preferences page.
The workflow for translators is described in Translate a Page.
Be aware that your contribution will be governed by the Gnu Free Document License and Creative Commons License, see KDE UserBase:Copyrights for details.
This is odd. I just checked your rights and you did not have translator rights. I gave you those rights, so you should be able to translate now. Have you made any translations on UserBase before? (If you have made translations on one of the other wikis but not here it would explain things as each wiki has its own rights.) Claus chr (talk) 18:11, 5 November 2020 (UTC)