SOLVED: language file for add-on plugin

Hi, I need your help! I didn't find enough help for this
we have an extra plugin for jem-joomlaeventmanager for cb. It works fine.
The english words and translations for frontend are in a old language file english.php and german.php. This works.
(When I compare this with other cblanguage files, there should be a newer style of language file.)

In the Tab Manager in my plugin in the Tab "Params" there is nearby all in english (no translation). How to create a translation file for this?

Thank you for any help.

Plugin translations are stored in the cbplugin folder of your CB language plugin found below.

/components/com_comprofiler/plugin/language/LANGUAGE_TAG

So for example you'd have the following for CB Activity.

/components/com_comprofiler/plugin/language/de-de/cbplugin/cbactivity-admin_language.php
/components/com_comprofiler/plugin/language/de-de/cbplugin/cbactivity-language.php

Notice that one is for "admin". That contains all backend only translations. To provide the default English translations for a plugin those should be placed in the language folder of your plugin shown below.

/components/com_comprofiler/plugin/user/PLUGIN/language/default_language

Using CB Activity as an example you'd have the below.

/components/com_comprofiler/plugin/user/plug_cbactivity/language/default_language/admin_language.php
/components/com_comprofiler/plugin/user/plug_cbactivity/language/default_language/language.php

You can try putting other defaults there was well, but that's untested however the code for them to load is there. So for example the below might work to provide default German translation for a plugin.

/components/com_comprofiler/plugin/user/PLUGIN/language/de-de/admin_language.php
/components/com_comprofiler/plugin/user/PLUGIN/language/de-de/language.php

Thank you kyle for your quick answer. But these things I just noticed.

But how a new language file should be and how the words in the plugin php?

For frontend I can use CBTxt::T( '...' ) in the plugin php, but then it seems to be hardcoded.

Do I need a key word, which then is used in the language file?

And is this the same for backend?

Are you trying to add translations to a 3rd party plugin? You do that using CBTxt API. You can use it as follows.

Simple
Key
You don't have to use a language key, but it makes things easier. They are mandatory though if the language string has substitutions like the following.

Thank you, Kyle. You made my day!

Sorry to disturb you again:

How I do it in Backend in the xml file?
it doesn't work with e.g.
label="CBTxt::T( 'JEMMYEVENTS_START', 'Startdate' )"