You can resend the offer email as long as holding deposit explained document hasn't been fully signed yet. To resend it do the following:

1. Open the tenancy overview page
2. In the "Offer" section click the 3 dots button (...)
3. Select and click "Resend offer"
4. You will see an option to choose who you want the offer email to be re-sent to
5. Select the individuals that you wish to resend the offer email to and click "Resend" button

The offer email will be re-sent to the individuals you have selected.