You will receive an email from CDSL once your bonus shares are credited to your Demat account. Initially, these shares are credited under a temporary ISIN. It usually takes 2-3 days for them to transfer to a permanent ISIN after trading approval.
During this period, the shares won’t be visible on your dashboard, but after approval, they will appear in your holdings and will be tradable.
No action is required from your side; the process is automatic.