# singer-tap-development


06/22/2021, 7:58 AM
Hey I am currently using the SDK to build a tap for and ran into an error error message: This error appeared when i tried to use
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poetry run tap-salesmate --discover
This is the member that is declared in the tap class
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config_jsonschema = th.PropertiesList(
        th.Property("lastActivityAt", th.DateTimeType, required=False),
        th.Property("instance_name", th.StringType, required=True),
        th.Property("sessionToken", th.StringType, required=True)
When I change all those required to False, The Command works fine. Help on fixing it is highly appreciated!