Have Qlik-Cli installed and configured (see Installing Qlik-Cli for more insight on how to install and configure Qlik-Cli)
Connect to the Sense site. Example command here(bolded text is configurable): Connect-Qlik -computername QlikSenseServer.company.com -username DOMAIN\UserName
Run Invoke-QlikGet command to the API path. Sample command: Invoke-QlikGet -path https://QlikSenseServer.company.com:4747/engine/healthcheck
Inspect the session JSON response for the number of active sessions: