upsertClientByExternalId: Client!
This mutation checks if a client exists if client already exists then that client is updated otherwise a new client is created. **Returns:** Returns the newly created client information along with a new Client ID.
client: ClientInput!
Client identification information.
externalIdentifiers: [ClientExternalIdentifierInput!]!
tenantId: UUID
The tenant that the client will be associated with.
demographics: DemographicsInput
Demographic information for new client.
insurance: InsuranceInput
Insurance information for new client.