Don’t make promises you can’t keep. If you’ve been vaping for a while, you may not be able to quit without help. Nicotine is a strongly addictive substance.
If this is your situation, rather than promising your parents that you will quit vaping, I would suggest promising that you will see your doctor, find out about treatment (counseling and medication, in most cases), and commit to scrupulously following the treatment plan. This is more realistic than saying you will stop right now on your own.