How to renew my reserve instance contract again which are about to expire ?

Set up renewal Refer the URL

https://learn.microsoft.com/en-us/azure/cost-management-billing/reservations/reservation-renew?toc=%2Fazure%2Fcost-management-billing%2Ftoc.json

Or Follow the steps

1)Go to Azure portal > Reservations.
2)Select the reservation.
3)Select Renewal.
4) Select Automatically purchase a new reservation upon expiry.

In case you don't renew the reservation
Your services continue to run normally. You're charged pay-as-you-go rates for your usage after the reservation expires.
If the reservation wasn't set for automatic renewal before expiration, you can't renew an expired reservation

Required renewal permissions
The following conditions are required to renew a reservation:
You must be an owner of the existing reservation.
You must be an owner of the subscription if the reservation is scoped to a single subscription or resource group.
You must be an owner of the subscription if it has a shared scope or management group scope.

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