This assumes you have already obtained a Bearer Token using curl. The following curl command can be used to determine if there is a certificate named foo.example.com. 

curl
--insecure
--quiet
--head
--request HEAD
--header "Authorization: Bearer abc123"
--header "Content-Type: application/json"
--url https://tpp.example.com/vedsdk/certificates/?name=foo.example.com

Something like this should be returned. Notice that X-Record-Count is 1. This means there is 1 certificate named foo.example.com.

HTTP/1.1 200 OK
Cache-Control: private
Content-Length: 0
Server: 
Access-Control-Allow-Origin: *
X-Record-Count: 1
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
Strict-Transport-Security: max-age=31536000; includeSubDomains
Access-Control-Allow-Origin: *
Date: Thu, 17 Jun 2021 11:36:05 GMT