I’m not sure if the approach works with 1011 and didn’t verify it as it is out of support.
On recent Cumulocity versions, you would extract the strings for translations using c8ycli locale-extract ./<path> with path being e.g. a subfolder src within your project, containing all of your code.
If you do not specify the path the will generate you multiple files, which also includes strings for translations from your node_modules, so also all default Cumulocity texts.
When path was specified, you should have received as an result a locales subfolder, containing a single file called: locales.pot. This file would be usually passed to a translation team, which would use tools like https://poedit.net/ to translate these texts into the languages you would like to support.
As a result of the translation process you would usually get a bunch of .po files, e.g. it.po for the Italian language.
You can then do an import of these files in e.g. the index.ts or more recent versions should also have a i18n.ts file for this specific purpose.
More samples and details can be found in the tutorial application.
There is no need for you to deal with .json files here.