Unfortunately not. You will need to reach out to your insurance broker (as applicable) or carrier to request the cancellation of your existing policy. When they process your cancellation, they will also process any refund owed to you.
Just make sure you choose an effective date for your Coalition policy that coincides with the expiration of your existing policy. All of our policies include full prior acts coverage by default, which is to say that we cover acts that occurred prior to your Coalition policy effective date provided they were first discovered during the policy period.