This is because there are some selections for eCommerce enabled on the TeamRaiser. If you would like to remove the button, you will need to disable the eCommerce options with the following steps:
  1. Go to Fundraising > TeamRaiser
  2. Select edit next to the desired TeamRaiser
  3. Go to step 3. Select Event Options
  4. Under Related Actions, select Edit Advanced Options
  5. Select Step e. Configure eCommerce Options
  6. If you are not using an eCommerce options with your TeamRaiser, unmark the selected options and save your changes.
This should make the button disappear.