How to pass variable to Azure DevOps Run Pipeline

I am trying to put predefined value RELEASE_RELEASENAME to Azure DevOps Run Pipeline task, but it ends always with error: "##[error]Build parameters is not a valid json object array. Example valid object: [{"VAR1":"VALUE1","VAR2":"VALUE2"},{"VAR1":"VALUE1","VAR2":"VALUE2"}]"

Azure Setup

You could try the change the expression of the variable like： [{"var1": "$(Release.ReleaseName)"}]