Error sending data to APM server: Read timed out, response code is -1

I have installed ELK 8.4.0 version and it is running successfully and installed elastic agent 1.8.1 version and apm server of 8.5 version. I have configured the tomcat application but while executing the server a found error as "Error sending data to APM server: Read timed out, response code is -1".

can u please help me out in that.