Connecting to Azure Analysis Services from Azure Synapse Analytics is not directly supported in the same manner as connecting from Power BI. In Azure Synapse, you can connect to various data sources including Azure SQL Database and Synapse Analytics itself, but Azure Analysis Services is not listed among the supported data sources for direct querying or data import within Synapse Analytics.
https://learn.microsoft.com/en-us/azure/analysis-services/analysis-services-datasource
https://learn.microsoft.com/en-us/azure/analysis-services/analysis-services-datasource#:~:text=,Yes%20Yes%20%E3%80%905%E2%80%A02%E3%80%91
https://learn.microsoft.com/en-us/azure/analysis-services/analysis-services-datasource#:~:text=Analysis%20Services%20Yes%20No
However, you could potentially use Azure Analysis Services as a source for SQL Server, which in turn could be accessed by Synapse Analytics.
https://learn.microsoft.com/en-us/azure/analysis-services/analysis-services-datasource#:~:text=SQL%20Server%20Yes%20Yes%20,17%E2%80%A08%E3%80%91
To establish such a connection, you would typically use the server name in the format <protocol>://<region>/<servername> and you would need the proper client libraries updated.
https://learn.microsoft.com/en-us/azure/analysis-services/analysis-services-connect
For more advanced scenarios, consider using a linked server approach from SQL Server to connect to Azure Analysis Services, but note that this method requires the use of the MSOLAP client library and is not the same as connecting directly from Synapse Analytics.