`StartOutboundVoiceContactCommand` Throws LimitExceededException: UnknownError in Lambda - Amazon Connect

I'm using the StartOutboundVoiceContactCommand from the @aws-sdk/client-connect package to initiate outbound calls from a Lambda function. However, every time I call this function, I receive the following error:

{
	"errorType": "Error",
	"errorMessage": "LimitExceededException: UnknownError",
	"trace": [
		"Error: LimitExceededException: UnknownError",
		"    at initializeCall (file:///var/task/index.mjs:84:15)",
		"    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)",
		"    at async Runtime.handler (file:///var/task/index.mjs:29:22)"
	]
}

Here's a snippet of my Lambda function where I'm using the StartOutboundVoiceContactCommand:

const initializeCall = async ({ DestinationPhoneNumber, ContactFlowId, InstanceId, SourcePhoneNumber, attributes }) => {
    try {
        const input = {
            DestinationPhoneNumber,
            ContactFlowId,
            InstanceId,
            SourcePhoneNumber,
            Attributes: attributes,
            AnswerMachineDetectionConfig: {
                EnableAnswerMachineDetection: true,
                AwaitAnswerMachinePrompt: false
            },
            TrafficType: "CAMPAIGN",
        };

        const command = new StartOutboundVoiceContactCommand(input);
        const response = await client.send(command);
        return response;
    } catch (error) {
        throw new Error(error);
    }
};

While I've implemented error handling in my code, I'm unsure about the service quotas. I'm still facing the LimitExceededException: UnknownError.

Has anyone encountered a similar issue or can provide insights into what might be causing this error? Any guidance would be greatly appreciated.