security – about installing SSL certification from for tomcat server

i am using tomcat version 9 and JDK 11, on ubuntu 20
Tomcat is working fine with domain name, i tried to use the certificate provided by with java apr, but its not working.

the ssl configuration in my server.xml is as below

 <Connector port="8443" protocol="org.apache.coyote.http11.Http11AprProtocol"
               maxThreads="150" SSLEnabled="true" >
        <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />
            <Certificate certificateKeyFile="/var/ssl/exampledomain.key"
                         type="RSA" />