How to check if a field is locked in Azure DevOps with Power Automate?

I have a Power Automate flow that updates fields in an Azure DevOps Release work item, but it's failing when the field is locked.

I only want it to update the field when it's not locked, but I don't know how to check the field's lock status.

Additionally, there seem to be two types of 'locked'. Most fields that show a lock will display the "< field name > is read-only" message (see screenshot), but the field I want to work with is the Planned Implementation End Date field, which shows a different lock symbol and doesn't display a message when hovered over. I don't know how or even if this might affect checking the locked status.

I've tried searching online and even asked ChatGTP, but I'm not finding a solution.

There is no method (REST API or CLI) to check whether a field is read-only in a work item on Azure DevOps.

If your projects really need this feature, I recommend you try to report a feature request on Developer Community to ask add this property to the returned response of Azure DevOps REST API and Azure DevOps CLI. This will make it more convenient for the Azure DevOps engineer teams to receive and understand your ideas. And your feedback also could be helpful for improving the Azure DevOps products.