How do you push yourself to exercise on days you are feeling more tired?

I tell myself that I need to make it because I promise myself to become a best version of myself.i need to make it even though I don't want to

All i need is to control my breathing and not to push to hard, for example i can just do some exercise like slow jogging, skipping or go up staircase. No need to push out self to harder because its gonna be bad for your muscle. Just do some exercise that can keep your fitness