I regularly download dSYM from the Activity tab in app store connect.
In that tab there are list of builds from their detail we can download the dSYMs.
But from today after After App Store Connect update, I have seen that there is no activity.
Apple Thread related to this topic.
So, From where I can download the dSYM?
I found the way to download the dSYM
Here I found a mail sent by the apple developer program support.
I'm with Apple Developer Program Support. I’m following up with you regarding your recent email.
I understand you are unable to locate the Activity tab in App Store Connect. I can certainly look into this for you. After researching your request, it looks like the Activity tab has merged with the TestFlight tab in App Store Connect. You can now see your build metadata under the TestFlight tab under your app record.
Update (17th Dec 2020):
Activity tab name changed to Mac Build Activity
Update (04th Dec 2022):
Find it under TestFlight Tab