When I purchased UA tickets back in late January for an autumn trip, the email with the "policies" arrived about 5 minutes after the flight confirmation.
You might try calling the insurance company with your flight confirmation number or write to them at [email protected]

Trip Insurance

A Travel Guard travel insurance plan through AIG Travel can help cover your trip investment, offset expenses from travel mishaps and provide you with emergency travel assistance.

Learn more or call 1-877-934-8308 if you are calling from the U.S. or 1-877-624-8196 if you are calling from Canada.