Hi @Matt Honeycutt ,
Yes, you should be able to. Have a look at https://learn.microsoft.com/en-us/rest/api/appservice/certificates/create-or-update. All that should be required is canonical and host names in the request body.
PUT https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/certificates/{name}?api-version=2019-08-01
{
"location": "East US",
"properties": {
"canonicalName": "My Managed Cert Name",
"hostNames": [
"ServerCert"
]
}
}