xUnit Theory with list of objects

Question

I am trying to use xUnit Theory to complete a unit test under different scenarios I have function that returns the 1st instance of an object that meets a certain criteria.

    public MyObject GetFirstObjectThatIsGzip(List<MyObject> obj){  

      return obj
      .FirstOrDefault(x => x.Key.EndsWith(".gz"));    
}

Unit test:

[Fact]
    public async Task GivenAlist_WhenMoreThanOneObject_ReturnTheFirstWithCorrectFormat()
    {

        var objectToReturn = GetMyTestObjects();

        _mockClient
            .Setup(x => x.GetFirstObjectThatIsGzip(It.IsAny<MyObject>())
            .ReturnsAsync(s3ObjectsToReturn);
            

        //Act
        var result = await _myService.GetDataAsync("myconnectionstring");

        //Assert
        Assert.Equal(result.Key, objectToReturnFirstOrDefault(x => x.Key.EndsWith(".gz")).Key);
    }

MyObjects:

        public static List<MyObject > GetTestMyObject()
    {
        return new List<MyObject >
        {
            new MyObject { Key = "ABC" },
            new MyObject { Key = "abc.json" },
            new MyObject { Key = "xzy.gz" },
            new MyObject  { Key = "lmno.gz" },
            new MyObject { Key = "rstu.gz" }

        };
    }

I want to know how to pass different lists of objects to one parameter that can be the return object.

[Theory]
[MemberData(nameof(GetTestMyObject), MemberType = typeof(MyObject))
public async Task GivenAlist_WhenMoreThanOneObject_ReturnTheFirstWithCorrectFormat(List<MyObject> objs)
{

    var objectToReturn = GetMyTestObjects();

    _mockClient
        .Setup(x => x.GetFirstObjectThatIsGzip(It.IsAny<MyObject>())
        .ReturnsAsync(objs);


    //Act
    var result = await _myService.GetDataAsync("myconnectionstring");

    //Assert
    Assert.Equal(result.Key, objectToReturnFirstOrDefault(x => x.Key.EndsWith(".gz")).Key);
}

I know that the Data Generator must implement IEnumerable<object[]> Can I change the IEnumerable<object[]> to be IEnumerable<MyObject[]> Also the unit test seems to give an error saying that the number of input parameters must match the number of items in the data I am generating ?

Does this make sense ?