[Plugin: NextGEN Gallery] two problems

1. Nextgen doesn’t appear in the setting menu in WordPress. How can I solve this problem?
2. Indor fútbol is a website in Spanish: https://www.indor-futbol.com. I downloaded the translation package from the NexGEN website. I renamed the lang folder in lang.bak. After that I uploaded the language folder from language package. NextGEN is still in English. Also my gallery is published in English. https://www.indor-futbol.com/fotos/
How can I get my NexGEN gallery published in the Spanish language?

Thank you for your help.

Markus

https://www.ads-software.com/extend/plugins/nextgen-gallery/