You have been previously advised on this very subject on your first thread.
You are still relatively new to budgie ownership and haven't yet taken the time to do the required research which will help you be better equipped and prepared to assist your pair and future chicks. The first step really is to take a more active role in getting to know your budgies, to study their behaviours, learn how to read and decipher their body language and how they interact with you and among themselves, in short to gain experience by taking a real interest in your budgies and being really open to learn by watching them.
The decision to breed comes with a whole lot of responsibility and commitment, the lives of the breeding pair and the chicks are depending on you and the response you give if/when faced with adversity.
Things like being able to tell if your breeding pair is in good health and top physical condition to go through breeding; when a hen is expecting an egg or if she is showing the first signs of being egg bound; when a chick is having developmental problems, not being fed or showing signs of dehydration;
when there is aggression, abandonment and neglect of the chicks and it's solely up to you to feed and raise the chicks. The ability to detect early on and solve these issues can truly make a difference on the outcome of your breeding journey.
Also the "letting nature take its course" motto is really not the best approach, these are pet birds hatched and raised in captivity for many generations and the "rules of the wild" don't apply to them because given the conditions in some cases they can breed to exhaustion and this would seriously impact the health of the breeding pair, leading in extreme cases to death.
Any chicks hatched from parents who are not in the best shape health wise will also directly suffer the consequences, they will be weaker and more predisposed to have illnesses and as a consequence, their lifespan will be greatly reduced.
It's also worthy of note that any potential chicks you might have, you would have to either take very strict measures to avoid matings/breeding or you would have to house the chicks separately by gender (males in one cage, females in another cage) in order to avoid inbreeding.
The same thing goes with housing the parents with the chicks.
For your current situation, it would be best to discourage your pair from breeding by following the recommendations on the link Julie has given you.
There is a wealth of information on budgie care and breeding on the articles and sticky threads. You can start by checking the info here at the Budgie Breeding section.
Also be sure to read this link: https://talkbudgies.com/budgie-breedi...s-new-old.html