Flight Cancellation Insurance

Does anyone know how it would be possible to get insurance that means you’d be reimbursed if you need to cancel your flights (especially going through Istanbul to St Petersburg)?

Most of the places I’m looking at buying tickets, either don’t offer refundable options or offer only partial refund at a hefty price? And my bank (and many other providers) won’t offer flight insurance to countries under sanctions or listed as “Do Not Travel”.

@SilentFog Your insurance won’t cover travel to Russia, as for most countries as you say its on the DO NOT TRAVEL list. If you are using Pegasus via Istanbul its possible to book a flexible flight option if you cancel before the date of the flight.