Who will own the accounts and credentials?
Ask whose accounts the workflows will run under, and who will hold the credentials for your CRM, inbox and accounting system. The answer you want is that your business owns the automation platform account and the credentials, and the consultant works with access you grant and can revoke.
Be cautious if the automation will run inside the consultant's own account or if credentials will sit in their personal workspace. That arrangement can make it hard to leave, hard to audit, and hard to rotate keys when someone departs.