Control Merge Request button through API or webhook to external tracking system

We have GITLAB Merge Requests to be approved by 2 peers and a team lead. I’d like an additional check to an external Issue tracking system to ensure the issue is in a particular state before allowing the “Merge” request button from being activated. Is there a way to control this? Perhaps adding another ‘approver’ which is an external checker and somehow tie that into a Webhook or API call.

Any ideas?