By default, the opt-out field is hidden within your Salesforce account. You might like to be able to see that after integrating your Enudge account with Salesforce. This article steps you through making that field visible.
Step 1: Go to Setup -> Object Manager -> Contact
Step 2: Click on Fields & Relationships in the Left Panel.
Step 3: Click on Email Opt Out.
Step 4: Choose Set Field-Level Security.
Step 5: Choose Visible and click Save.
Step 6: Go back to Contact List. Choose Select Fields to Display.
Step 7: Add Email Opt Out to the Visible Fields list and click Save.