Currently, the attestations cannot be sent to users who are not part of the system. My understanding is it can only be sent to internal users who have some role in the system.
We have a requriement where we would like to send to all vendor employees who have access to our environment an Acceptable Use policy for them to attest.
At the moment, we are planning to work around with some existing features.
We have created a questionnaire where the custom introduction is essentially the content of the policy. We then created a question which asks "Do you acknowledge and agree" with a "Yes/No" option.
Ideally, since you have the Attestation feature, it would be great if we could use attestation feature for this and if its linked to the Third Parties list. This way, we can see for a specific vendor, if they have completed their assessments, what risks they have and how many of their employees completed an attestation