You can find the language file – cpm.pot inside the plugins language folder, which can be found at wp-content/plugins/wedevs-project-manager/languages.
You'll have download and rename it to cs_CZ.pot and open it with an Editor, like PoEdit. When you save it after translating, there will be one more file created: cs_CZ.mo. Upload both the files in wp-content/plugins/wedevs-project-manager/languages.
This would work for sure. And please share the language file with us after translating.
thank you for your response. I thought it otherwise. I know where I can find the language files in WP. I wanted to know where I can find any ready-made / translated language files a repository where all translated already are and where you can download ..?