Move your body more. Especially, bend your spine in both directions: extension and flexion. Do it a lot. And it should feel challenging. Like working out. Do it in every position imaginable.
Lots of stretching / staying limber
Neck retractions
Pilates training / deep core exercises
Have never tried one of these posture correctors, could imagine they help but prob it‘s just 5%.
Biggest thing for me is Not looking down all day at the Laptop and not „working“ from the Couch aka fucking up posture consistently.
Good strength & flexibility training is key to improve and build some resistance too.