Add a new administrator
If you are the current administrator, sign in to your Google for Nonprofits administrator account with the email address you used when you applied for Google for Nonprofits. (It may be different than the account you use to access other Google products.) Click on your organization's name. Enter the email address (must be a gmail.com or G Suite account) and name of the new person. Click the blue 'Add Administrator' button. Both parties will receive an email confirming access.
If you are NOT the current administrator, you must first submit an administrative access request. See Request administrative access for instructions. Once a request has been filed, the current administrator can approve the request by signing into his or her Google for Nonprofits account. See Approve or deny an administrative access request for instructions.