Please solve the programming task below using a self-contained code snippet in a markdown code block.

The array-form of an integer num is an array representing its digits in left to right order.

For example, for num = 1321, the array form is [1,3,2,1].

Given num, the array-form of an integer, and an integer k, return the array-form of the integer num + k.
 
Please complete the following python code precisely:
```python
class Solution:
    def addToArrayForm(self, num: List[int], k: int) -> List[int]:
```