from Jmeter ---> target url

download the CA/chain from target url from browser, and add it to the JVM/JAVA ca, on which Jmeter is running.

or start the jmeter with trust store where you have uploaded the certificate and its corresponding CA

-Djavax.net.ssl.trustStore=path/to/your/truststore.jks -Djavax.net.ssl.trustStorePassword=your_password

jmeter -n -t test_plan.jmx -l result.jtl -Djavax.net.ssl.trustStore=path/to/your/truststore.jks -Djavax.net.ssl.trustStorePassword=your_password