The If-Match header contain invalid value

Question

I want to update the title of a planner using graph api as per this documentation https://learn.microsoft.com/en-us/graph/api/plannerplan-update?view=graph-rest-1.0&tabs=http where it mentioned to send this request:-

so i am sending this request using send http action inside a power automate flow (also i tried the same inside postman) :-

but i am getting this error :-

"The If-Match header contain invalid value"

I also tried without W/ >> so I only pass this value "JzEtVGFzayAgQEBAQEBAQEBAQEBAQEBAWCc=". But got the same error as before.

any advice what should be the If-Match header for my request?

so not sure why it is not accepting the If-Match, although i specify the exact value as per the documentation.

any advice?

Thanks