As a follow up to the solution of @InesTeixeira
You can add the descriptions with the desired language code in a supported way as follows:
Add language package
First you need to add the language package of the target environment to your source environment.
Go to admin.powerplatform.microsoft.com and open your source environment where you want to export the solution from. Go to Settings - Product - Languages. Choose the language of your target environment and "Apply".

This might take some minutes.
Add translations to solution
When the language package is added, go back to your solution and click Translations - Export translations:

This will download a zip-folder. Unzip it and open the file "CrmTranslations.xml" in Excel. There you see a empty column with the language code of the package you just added (in my case 1031 for German). Populate the translations. I just duplicated my values from the English column (1033) as I didn't need any translation.

Save the file. Go back to your unzipped folder. Select both files and zip them (Send to - Compressed (zipped) folder).

Go back to your solution and click Translations - Import solutions. Choose your newly zipped-folder.
Export your solution and import it to the target environment.
Best regards
Carole