TeamPages gives you the option to add members for a specific Team via CSV.
1. On your Team's TeamPage site, click on the Roster menu link.
2. Determine the role and then click on Add Members+.
3. On the Add Members page, click on the Add via CSV tab.
4. If you have CSV file ready, just click on Choose File button and locate the CSV file. Once the file has populated (just below it), click on Upload.
*** Make sure to take note the highlighted section as it provides the requirement for setting up the CSV file that needs to be uploaded.
For additional CSV upload/import information, you can try to check --
https://support.activenetwork.com/teampages/articles/en_US/Article/Bulk-Import-Members-18
