The Host or Co-Host can share their fundraisers with others in your Zoom Meeting or Webinar by clicking "Feature your Fundraiser on Zoom," once the fundraiser has been either created or selected. 

You will then see this message from Zoom, click Allow

Meeting attendees will then receive an invitation to use the Zoom App. It is important that all attendees are using the most latest version of Zoom. If they are not, they may not receive the invitation. 

After an attendee clicks "Open" they will see the Donations by Pledge app in Guest Mode and will be able to donate to the fundraiser.