@Mauricio González Thank you for reaching out to Microsoft Q&A. Apologize for the inconvenience caused on this.
Based on the shared scenario, I have understood that you are trying to pull the public certificate present on the web app. you can use the Azure Management REST API WebApp-List Public Certificates to pull the list of public certificates on the web app.
While testing the above cmdlet in my local environment i see that az webapp config ssl list
is giving me the list of private certificates only as shown below.
Feel free to reach back to me if you have any further questions on this.