Oxygen has rudimentary support for WPML and Polylang.
This is not an official feature of Oxygen and no support will be provided via official support channels.
Note that the Oxygen and WPML teams have been in contact and are jointly investigating official compatibility. This does not mean that WPML compatibility is planned or guaranteed at this time.
Information on translating content created in Oxygen can be found on WPML's website.
Caveats that we're aware of:
Template translation doesn't work for logged out users. As such, you will need to use one template, duplicate your content, translate it within the same template and then use Conditions to show/hide the content based on the language string in the URL.
WPML and Polylang usually prevent you from being able to save changes to Reusable parts.
Please report issues on GitHub.