When it comes to managing stress, I find it helpful to think in terms of preventative practices and in the moment practices. It's unrealistic to think that we can avoid stress altogether, nor do we truly want to as some stress is good for us, so having a toolkit with both options ensures that we are ready for anything.
What I love most about yoga is that it offers both preventative benefits and in the moment tools for stress management. As a preventative practice, yoga encourages you to relax, slow your breath, and focus on the present, shifting the balance from the sympathetic nervous system (aka the fight-or-flight response) to the parasympathetic nervous system. The latter, sometimes called rest and digest mode, is calming and restorative; it lowers breathing and heart rate, decreases blood pressure, and increases blood flow to the intestines and reproductive organs. These same techniques practiced during yoga can be applied in a moment of stress to reconnect us to the present, and lessen feelings of anxiety, overwhelm and lack of control which are common characteristics of stress.
You don't have to be flexible to practice yoga. All you need to be able to do is breathe (something we are all exceptional at 😊) and be willing to slow down. Yoga is also something that you can practice in the comfort of your own home. There are lots of free options available online. My favourite is Yoga with Adriene.