Kindly provide the guidelines on integrate Network traffic flow integration with Splunk cloud instance.
from your network devices, can you send the logs as syslog to a syslog server and configure splunk UF to read them and send it to cloud? This way you can send logs from more than one device [ via syslog] to syslog server [ e.g. rsyslog or syslog-ng installed on a linux platform] and onward to splunk cloud.
Pls also raise a support case with splunk cloud to agree the approach.
Are you trying to on-board data from a particular vendor? did you check if there are any supporting add-ons?
Generally, if you can the logs/traffic on to a Universal forwarder (UF), that can be configured to send them to the splunk cloud [ you would need to work with cloud support to connect your UF to connect to cloud via certs]