TypeConverter cannot convert from System.String nintex workflow for sharepoint

I tried to initialize a collection variable in Nintex workflow

I set the value to

[{"Rating":""}]

When I publish the workflow I get the below error

TypeConverter cannot convert from System.String
Is the format incorrect?

+13

That default value format looks more like a dictionary than a collection.

Dictionary are not available in NWC.

You could create a collection variable with no default value,

Then use an add item to collection operation to add a value into the collection

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