SQL Server Certificate error on Kubernetes - sql-server

Question

I have a Spring Boot rest service which retrieves data from a SQL Server Database. It runs fine on local but on deploying to the Cloud environment, the POD fails to come up and we are seeing certificate issues, I see the below logs:
[main] ERROR com.zaxxer.hikari.pool.HikariPool - HikariPool-1 - Exception during pool initialization.
com.microsoft.sqlserver.jdbc.SQLServerException: The driver could not establish a secure connection to SQL Server by using Secure Sockets Layer (SSL) encryption. Error: "PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target". ClientConnectionId:<random generated id>
at com.microsoft.sqlserver.jdbc.SQLServerConnection.terminate(SQLServerConnection.java:3680)
at com.microsoft.sqlserver.jdbc.TDSChannel.enableSSL(IOBuffer.java:2113)
.............................................
.............................................
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:65)
Caused by: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at java.base/sun.security.ssl.Alert.createSSLException(Unknown Source)
.............................................
.............................................
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSChannel.enableSSL(IOBuffer.java:2021)
... 58 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at java.base/sun.security.validator.PKIXValidator.doBuild(Unknown Source)
.............................................
.............................................
at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSChannel$HostNameOverrideX509TrustManager.checkServerTrusted(IOBuffer.java:1702)
at java.base/sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(Unknown Source)
... 71 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
at java.base/java.security.cert.CertPathBuilder.build(Unknown Source)
... 79 more
The connection string: jdbc:sqlserver://<HOST_NAME>:<PORT_NAME>;instanceName=<INSTANCE_NAME>;databaseName=<DB_NAME>;
I have tried adding encrypt=true; trustServerCertificate=true; and trustServerCertificate=false; as suggested on different posts but it still fails.
I have seen this error for different URLs in the past and the fix would be to download the Certificate (using the browser) and adding it to the Java KeyStore but I am not sure what to do for Databases. Also, we wouldn't have access to the Java Keystore on the cloud env.
Can someone help/guide on how to fix this issue?
Thanks in advance.