The documentation about Azure DevOps and Azure Service Bus integration is a bit blurry, but when connecting a service bus as a service hook to Azure DevOps, copy the SAS (Shared Access Token) connection string from Azure Portal and paste it without the EntityPath and ; to the connection string of Azure DevOps to make it work.
This is the connection string on Azure Portal:
Endpoint=sb://selcuk.servicebus.windows.net/;SharedAccessKeyName=ado;SharedAccessKey=FAKE=SAS=4FjStU5nBWH4F0PF/HXjgGQMA=;EntityPath=myQueue
This what should be pasted on Azure DevOps:
Endpoint=sb://selcuk.servicebus.windows.net/;SharedAccessKeyName=ado;SharedAccessKey=FAKE=SAS=4FjStU5nBWH4F0PF/HXjgGQMA=