Hi Jason,
From Microsoft Access you would use TCP port 1433 to connect to Synapse SQL Serverless Pool, assuming you are connecting from outside of Azure via Internet. TCP 443 and 1443 are used by Synapse Studio.
Please see articles below for more information.
Synapse Connectivity Series Part #1 - Inbound SQL DW connections on Public Endpoints
Connect to Azure Synapse from your own network
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Thanks.
-TP