Hey.
You eat all the insides and leave the crust… my attempt at humour.
What you do is make a pie, add one stock. I normally use Apple as the US opening hours are key to how I use the pie.
I am in the UK, so the US stock exchange does not open until the afternoon for me.
So before the stock exchange opens, I add the money I want to save to the pie with the Apple stock in it, you will get a pop up saying it will complete the investment when the stock exchange opens, tap ok, then at the top of the pie you will see a progress bar, click on this and click cancel. This will stop the transaction completing, but will leave the funds in the pie, uninvested, so they will also earn interest.
IT IS IMPORTANT THE STOCK EXCHANGE THE SHARE SITS IN IS CLOSED before you send the buy order and then cancel it. This is why I use the USA, as on my pay day, I deposit funds into my trading212, buy the shares I want to and then put some away into my empty pie for my savings targets in the morning before the exchange opens.
This is an unofficial way of doing this and is it at your own risk.