Failed to parse the field

I am sending logs to kibana using filebeat ,and I am facing below error while sending logs .Some of the events doesn't have host in raw data facing error for that events.

[2020-09-24T09:20:40,591][WARN ][logstash.outputs.elasticsearch][main] Could not index event to Elasticsearch. {:status=>400, :action=>["index", {:_id=>nil, :_index=>"filetest-", :routing=>nil, :_type=>"_doc"}, #LogStash::Event:0x6eb22ef8], :response=>{"index"=>{"_index"=>"filetest-", "_type"=>"_doc", "_id"=>"keBFwHQB9GB4WNUD5v0d", "status"=>400, "error"=>{"type"=>"mapper_par Preformatted text sing_exception", "reason"=>"failed to parse field [host.hostname] of type [keyword] in document with id 'keBFwHQB9GB4WNUD5v0d'. Preview of field's value: '{}'", "caused_by"=>{"type"=>"illegal_state_exception", "reason"=>"Can't get text on a START_OBJECT at 1:603"}}}}}

Please help me out

Take a look at Can't get text on a START_OBJECT, it is the same error.