The doubt of SubscriptionType in EventDestination

According the schema as below,

"SubscriptionType": {
"anyOf": [
{
"$ref": "#/definitions/SubscriptionType"
},
{
"type": "null"
}
],
"description": "The subscription type for events.",
"longDescription": "This property shall indicate the type of subscription for events. If this property is not present, the SubscriptionType shall be assumed to be RedfishEvent.",
"readonly": true,
"versionAdded": "v1_3_0"
}
}

As my understanding, "SubscriptionType" is not a required property in a request when we create a subscription.
But like the example, If we want create a SNMP subscription, we need to change the "Protocol" as "SNMPv1" or "SNMPv2c"...etc.
Do we need provide "SubscriptionType" in request?

Thanks,
Archer.