You can leverage the use Dynamic Translation to translate any field of a form.  This will give you a seamless localization experience.

OOB we are shipping with MS/IBM. You can utilze these OOB flows and can customize your own Translators

More info

While you are integrating with a custom translator you may hit with various errors on the form's or in the flow context. For troubleshooting known errors you can refer the docs

This KB reffers to the common error code while integrating with a custom translator: "code":"40051","message":"Unknown error occurred"

NewYork above

One among the reason for this error could be the subflow input/outputs for custom translator different. It should follow the same input/output contract in similar to OOB subflows like MS/IBM.

To check this

1. Navigate to:  Dynamic Translation > Translator Configurations

2. Locate your Translator 

3. Check for "Detect Subflow" and "Translate Subflow"

4. Compare the flow with the OOB translator flows.

You could see the errors in the Node/logs as

JavaScript evaluation error on:
sn_dt_api.DynamicTranslation.getTranslation("test");
Root cause of JavaScriptException: com.glide.dynamictranslation.DynamicTranslationException
: {"code":"40051","message":"Unknown error occurred"}:

Your custom flow should follow the same input/output contract in similar to OOB subflows like MS/IBM. If you are using custom script, also make sure the declarations and mappings are proper.

Flow looks as follows