How to resolve -- NoSuchMethodError: com.mongodb.client.MongoCollection.insertMany

Oh okay …what should I specify sir
Like the error occur when I’m trying to save the data into my local mongodb.
Maybe I’m not elaborative. I also think so it’s due to dependency issue.

Let me be very precise that. how this issue came –

The application was fine before I was using the older version of springboot
, mongodb and spring-boot-gradle-plugin was 2.2.5.RELEASE .
Then I wrote a query where I have to use UnionOperator of mongodb but it was 
not supported in the older version.
So, I upgraded  spring-boot-gradle-plugin  to the latest version (major change
was the spring-boot-gradle-plugin because when I changed it to the latest or
 above 2.3.12.RELEASE then I was able to use the UnionOperator
But then It started showing me errors. 

To use unionOperator I was forced to change the “spring-boot-gradle-plugin” 
because I upgraded springboot-mongodb and mongodb-driver to it’s latest but 
that didn't work .
And then I upgraded  spring-boot-gradle-plugin which works but then, it showed me this error