Create a duplicate of a template in another app. The new template will be completely separate from the original (including having a new template_id) but will be created with all the same content.
app_id) to another (target_app_id). The duplicated template will have the same content as the original, but a new unique template_id.
app_id and target_app_id must belong to the same Organization.template_id (path param): UUID of the template to be copied.app_id (query param): ID of the app where the original template exists.target_app_id (body param): ID of the app where the template will be duplicated.template_id (UUID v4). You can find it:

Copy Template ID
app_id and target_app_id.
template_id for the copied templateYour Organization API key with prefix Key. See Keys & IDs.
Your OneSignal App ID in UUID v4 format. See Keys & IDs.
Specifies the OneSignal app ID that the template will be copied to. Cannot be the same as the app_id.
200
Whether the template was copied successfully.