Hello @jackchen198712
In order to communicate with Neo4j 5.15.0 you should use a Neo4j driver with a version no less than 4.4.0.
As you are using 5.15.0, please consider using the latest driver, it has many improvements over 4.4.0
Neo4j Drivers from v4.4.0 and 5.0.0 to 5.16.0 all support .NET standard 2.0 so should be compatible compatible with your .NET Core 2.0 project.
As a side note I would recommend using .NET 6 or 8 as .NET Core has been out of support for 5 years.