All paid Clockwise accounts have a billing admin – often the person who first entered payment details into the account. You can find your billing administrator(s) within the Plans & Billing area of the Clockwise web app. If your paid team has more than 1 admin, hovering over the "# others" will display those who are able to affect billing details.
If you are a billing admin, you will find a button, "Manage billing details" under in the Plans and Billing area. This button is only present if you are a billing admin.