If you need to change the details of your account, you can do that on your Ramp profile. Head to Settings --> Profile --> Edit profile to update your number or email address.
From there, put the updates you need on your account. Ramp will send you a verification code to your email or phone number afterwards then you'll be all set!
If you need to update the emails of many users, Ramp's Customer Operation team is happy to help. Just email support@ramp.com.