Ntopng flows to opensearch

Versions (relevant - OpenSearch/Dashboard/Server OS/Browser):
Opensearch version: 2.7.0
ntopng version: 5.3.0

Describe the issue:
I am currently ingesting data from ntopng to elasticsearch version 7.16.3 using following command:

ntopng -i ens4f2 -F "es;flows;nflow1%Y.%m.%d;http://192.168.0.155:9002/_bulk?pipeline=rttgep;"

Now I want to send this data from ntopng to opensearch
but I am facing following error:

Relevant Logs or Screenshots:

05/Jul/2023 11:31:05 [ElasticSearch.cpp:202] ERROR: ES: POST request for 15 flows (18401 bytes) failed
05/Jul/2023 11:31:08 [ElasticSearch.cpp:195] ES: Buffered request with 20 flows (24848 bytes)
05/Jul/2023 11:31:09 [Utils.cpp:1362] [JSON] {“error”:{“root_cause”:[{“type”:“illegal_argument_exception”,“reason”:“Action/metadata line [1] contains an unknown parameter [_type]”}],“type”:“illegal_argument_exception”,“reason”:“Action/metadata line [1] contains an unknown parameter [_type]”},“status”:400}
05/Jul/2023 11:31:09 [Utils.cpp:1562] Posted JSON to http://192.168.0.168:9200/_bulk?pipeline=rttgep
05/Jul/2023 11:31:09 [Utils.cpp:1460] [NAMELOOKUP_TIME 0.00][CONNECT_TIME 0.00][APPCONNECT_TIME 0.00][PRETRANSFER_TIME 0.00][REDIRECT_TIME 0.00][STARTTRANSFER_TIME 0.01][TOTAL_TIME 0.01]
05/Jul/2023 11:31:09 [Utils.cpp:1570] WARNING: Unexpected HTTP response code received 400
05/Jul/2023 11:31:09 [ElasticSearch.cpp:202] ERROR: ES: POST request for 20 flows (24848 bytes) failed
05/Jul/2023 11:31:10 [ThreadedActivity.cpp:288] Running /usr/local/share/ntopng/scripts/callbacks/5second/system/upload_timeseries.lua (iface=0x559733ddaa60)
05/Jul/2023 11:31:11 [ElasticSearch.cpp:195] ES: Buffered request with 15 flows (18758 bytes)
05/Jul/2023 11:31:11 [Utils.cpp:1362] [JSON] {“error”:{“root_cause”:[{“type”:“illegal_argument_exception”,“reason”:“Action/metadata line [1] contains an unknown parameter [_type]”}],“type”:“illegal_argument_exception”,“reason”:“Action/metadata line [1] contains an unknown parameter [_type]”},“status”:400}
05/Jul/2023 11:31:11 [Utils.cpp:1562] Posted JSON to http://192.168.0.168:9200/_bulk?pipeline=rttgep
05/Jul/2023 11:31:11 [Utils.cpp:1460] [NAMELOOKUP_TIME 0.00][CONNECT_TIME 0.00][APPCONNECT_TIME 0.00][PRETRANSFER_TIME 0.00][REDIRECT_TIME 0.00][STARTTRANSFER_TIME 0.01][TOTAL_TIME 0.01]
05/Jul/2023 11:31:11 [Utils.cpp:1570] WARNING: Unexpected HTTP response code received 400
05/Jul/2023 11:31:11 [ElasticSearch.cpp:202] ERROR: ES: POST request for 15 flows (18758 bytes) failed
^C05/Jul/2023 11:31:13 [main.cpp:50] Shutting down…
05/Jul/2023 11:31:13 [PeriodicActivities.cpp:100] Terminated periodic activites…
05/Jul/2023 11:31:14 [ElasticSearch.cpp:195] ES: Buffered request with 23 flows (28992 bytes)
05/Jul/2023 11:31:14 [Utils.cpp:1362] [JSON] {“error”:{“root_cause”:[{“type”:“illegal_argument_exception”,“reason”:“Action/metadata line [1] contains an unknown parameter [_type]”}],“type”:“illegal_argument_exception”,“reason”:“Action/metadata line [1] contains an unknown parameter [_type]”},“status”:400}
05/Jul/2023 11:31:14 [Utils.cpp:1562] Posted JSON to http://192.168.0.168:9200/_bulk?pipeline=rttgep
05/Jul/2023 11:31:14 [Utils.cpp:1460] [NAMELOOKUP_TIME 0.00][CONNECT_TIME 0.00][APPCONNECT_TIME 0.00][PRETRANSFER_TIME 0.00][REDIRECT_TIME 0.00][STARTTRANSFER_TIME 0.01][TOTAL_TIME 0.01]

Can nayone tell, how to fix this issue?