You can manage your contacts at manage.yodel.io/contacts.
There, you can do a whole bunch of things including:
1. adding a new contact (by clicking on "new contact")
2. editing an existing contact (click on the name in the contact list)
3. block a contact. Blocked contacts will be filtered out which means that those contacts are not able to reach your Yodel number.
Get in contact with our support if you need to upload a big number of contacts so we can do this for you.
You can also add a contact with a Yodel command directly in Slack.
With the Yodel command /yodel-contact you can save a contact by typing the contact's number with the international area code (e.g. +1 for the US) and adding the contact's name. All future incoming calls from that saved number will get displayed with the chosen contact's name: