[Vuejs]-[Vue warn]: Invalid prop: type check failed for prop "productCartData". Expected Object, got String with value "[object Object]"

You cant pass getter cart of array as params in router link. if you want access getter of cart into your component just access it directly in that component.

or you don’t event need getter. just create a computed property in your component.

params can only be string or number and they need to be declared in router

read for params.
https://next.router.vuejs.org/guide/essentials/dynamic-matching.html

to access objects arrays from store or data of components just use computed property.