How to get all item from local storage in blazor?

I'm planning on create a get all item for local storage to pass in Indexed DB. I'm using Blazor WASM. This local storage code is fromretrieve all localStorage items . I have this few error

Invalid expression [, syntax error value expected

'object' does not contain a definition for 'keys'

 private void allStorage(){   //error Invalid expression [    var values = [],        //error keys        keys = Object.keys(localStore),        i = keys.length;    while (i--)    {        values.push(localStore.GetItem(keys[i]));    }    return values;}