Kinesis Data Firehose supports delivering data to Splunk clusters using ALB

Amazon Kinesis Data Firehose (Firehose) enables customers to capture, transform, and deliver data streams into Amazon S3, Redshift, OpenSearch, Splunk, and 10+ other destinations for analytics. With this new feature, customers can now use Firehose to deliver streams to their Splunk cluster configured with either an Application Load Balancer (ALB) or a Classic Load Balancer (CLB). 

Source:: Amazon AWS