In $function operator external library like moment.js not supporting

Currently, I am using m10, The $function operator is supported but external libraries like moment.js are not supported in the aggregation pipeline.

Hell @Sakil_Hossain, Welcome to the MongoDB community forum,

The $function does not support any external libraries!

Why do you need this kind of operation in a query? Make sure you have read the Note in the documentation,

Executing JavaScript inside an aggregation expression may decrease performance. Only use the $function operator if the provided pipeline operators cannot fulfill your application’s needs.

Always try to use this kind of operation on your client-side or server-side instead of a database query.