We have an integration that uses the older API’s. For example I just make a cURL request to
https://a.klaviyo.com/api/v1/lists?api_key=xyz
Will I still be able to do this by passing the api_key with v3 endpoints or do I need to authenticate first with oauth now?
And if so can I just convert to the lack of a v# like the docs say is not used anymore?
For example: https://a.klaviyo.com/api/lists?api_key=xyz ? is that all that is needed?