how to add multiple issuers profile in a single certificate?
That’s not something that is supported at this time. You could try it, but you’ll be changing code in order to do it. The tricky part would be that the current code expects the private keys to be the same both for signing certificates, and anchoring to the blockchain. It also expects the certificate signing key to remain the same for all certificates.
You might be able to get away with changing the code to accept multiple private keys. You’d have to make sure you get all of the touchpoints, such as creating the Merkle tree, what to do about signing transactions before broadcasting them to the blockchain (you can only sign a transaction with a single key), etc.