SKAdNetwork Postback Validation Signature

To verify the signature we have to create an "X.509 standard public key" but it doesn't say what type key it is. Is it rsa, dsa, ecdsa or ed25519?

I'm trying to create this key with the byte array but I'm getting an unsupported elliptic curve error
Does anyone have an answer for this mystery?
SKAdNetwork Postback Validation Signature
 
 
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