I appreciate people coming here to look for guidance on the process but do keep in mind we are all competing for one of 30 spaces and there will be thousands of us.
What you can do in the meantime is book an initial class 1 medical if you do not already have one. Regardless of whether or not you get a place on a course or you go the modular path, a class 1 is necessary to be a commercial pilot and TUI will require you to have one as a condition of an offer.
It can take a few months to get a booking and any further investigations needed can take months of back and forth between the CAA and specialists. Do not assume you will be able to pass the class 1 initial on the day, even the smallest of things can require being referred to a specialist.
CAA Medical standards can be found
here.
I'd also recommend booking a trial flight at a local flight school or club if you have no flying experience. It will be around £200 for the hour flight and you'll be able to control the aircraft once up in the air. This will give you an idea of whether or not you like being in control and if you can stomach being in a light aircraft. Working towards a PPL in 2023 will make it an exciting and highly rewarding year. Airliners may be the goal, but being up in the air by yourself at 5000ft in a little Cessna is a magical feeling.
A PPL is the first step on the modular path and will also be a great addition to an MPL which does not allow you to fly single engine aircraft by yourself.
Finally - familiarise yourself with what is involved in the ATPL course. 14 exams over 6 months is very intense and there is a huge amount of knowledge to absorb. This stage is typically thought of as the most challenging, even when completed over a longer period as part of modular training. If you have been out of education for a while or pursued a vocational path, the biggest hurdle will be figuring out how to study effectively at what I have been told is degree level. The Pooleys PPL theory books would be a good warmup.
For the sake of sanity, expect to hear nothing back and treat the process so far as valuable practice and learning for applying to future programs or directly entry fATPL jobs.
Have a happy new year everyone!