Does anyone know how to make calls with a certificate?

Does anyone know how to make a call with a digital certificate on Postiman? You have the option of putting the certificate and the calls work. I went to make it on the N8n and got this error ERROR: Bad request - please check your parameters
400 - “\r\n400 No required SSL certificate was sent\r\n\r\n400 Bad Request\r\nNo required SSL certificate was sent\r\nserver\r\n\r\n\r\n”