The Campaign Member option is only available for Update when using Data Import Wizard. This means that you can use Data Import Wizard to update existing campaign members with new or modified information, but you cannot use it to create new campaign members from a spreadsheet. To create new campaign members from a spreadsheet, you need to use other tools such as Data Loader, Import Wizard for Leads and Contacts, or Manage Members button on the campaign page. References: https://help.salesforce.com/s/articleView?
id=sf.campaigns_members_adding_parent.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.
data_importer.htm&type=5