@Venkata Kartik Sadam I think you have installed the required version on the compute instance but while running the notebook the kernel environment cannot find one. I have seen a discussion on SO thread to use the same 8.6 version where you need to install the same on compute instance and create a new environment that can access the same. Please see the referenced SO thread and check if the steps in the answer provided works.
Ref: Answer provided on SO threadby ladams.
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