Need help in send and receive string set up for F5 ECV monitor when response is in json format

Hi Team,

I am trying to set up monitoring for F5 load balancer pool. I am using below send and receive string however it does not work. It always shows status as RED even if server is UP.

Send string : GET /actuator/health HTTP/1.1\r\n -H Host:<host>

recv string :  \"UP\"

https://<url>/actuator/health is used for health check which returns response in json format as below.

{"status":"UP","groups":["liveness","readiness"]}

Could you please help what should be the correct recv string which we should set up so that monitoring works.