Vision6 is capable of sending DMARC compliant email because they support custom SPF and DKIM configurations that achieve DMARC alignment. Vision6 is an Email Marketing Platform and is often used by Marketing and Product teams. Review their email authentication support articles to get a better idea of their offering and approach.
To set up DKIM successfully, please work with Vision6 support resources.
Though they touch on how to configure SPF in their documentation, we still recommend contacting their support to ensure your plan with them is eligible.