Add new field to index using Logstash getting null values

When the logstash finish the index processing stops and say:

[INFO ] 2019-02-07 16:25:47.671 [[main]-pipeline-manager] pipeline - Pipeline has terminated {:pipeline_id=>"main", :thread=>"#<Thread:0x4ea6dc5 run>"}

it is possible to keep the config file working in real time in such a way that when the index gets new data, it will be processed with logstash?