Issue with custom MongoDb Adapter creation for Biztalk Server 2020

I have a custom Adapter in BizTalk 2020 that reads data from MongoDB GridFS. But since the code was earlier in 2013 R2 Framework, now while migrating it to 2020 Framework, it throws error like

IAdapterInterface is not implemented

I then added this Microsoft.Adapter.Biztalk.AdapterFramework namespace in my projects so now I inherited the IAdapterInterface.

How do I implement its methods(GetConfigSchema() ) to load the Receive handler/send handler/ schema in property browser in Biztalk admin console?