Github Action - How can I trigger a workflow when argocd deployment is finished

Question

I work for a company that makes use of Github Actions and Argocd (using argocd helm chart). Needless to say, the Github repository is private, and argocd is located on an internal network that is only used by the company.

What we want to do is trigger another workflow that will run tests on the deployed environment when we deploy the app and it succeeds. In essence, the deployment will serve as a trigger for another workflow.

I've been attempting to configure a webhook from argocd to github without success. What is the best approach to this situation? I am happy to provide additional context if necessary.