Good day, reef_christy.

Thanks for choosing QuickBooks.

I understand that you want to receive donations through the invoices you sent. However, this option isn't available. Instead, you'll want to add a new line item on the invoice for the donation.

Also, they have an option to edit the amount when they pay online. They can click the Pencil icon in the Payment Amount field and add the donation from there.

Please check this link for more details on how to take and process payments in QuickBooks Online.

Keep on posting if you have more questions. I'll be here!