You'll need to also install the compatible version from Scanco.
If they have MB, you can find the installer on this page, Download Library - Scanco Multi-Bin - Sage Warehouse & Manufacturing Automation.
If they just have the handheld solution that uses the Mobility For Barcode, you would typically need to install the updated version as well. However, I only see an installer for 2020.5 on this page, Download Library - Scanco Downloads - Sage Warehouse & Manufacturing Automation. May need to get Scanco to send you an installer for 2020.3 or confirm the 2020.5 installer is compatible.
Alternatively, you may want to consider updating the client to 2020.5 if possible since Scanco has installers for both MB and BC for 2020.5.
Worse case scenario, if they just have BC and nothing else, you may be able to get away with installing PU3 and leaving BC alone.
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David Speck II
Blytheco LLC
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