Under Payment Methods select "Stripe ACH", this will open a new page where you can "Add New Bank Information".
You will see a popup notification about us now using Plaid, click Continue. Select your bank and enter your banking login information. It will ask for permission to access various areas and information of your bank account, this is ok, click Continue. After that point you should have a verified bank account and can pay the invoice, you can also now use that bank account as an automatic payment option for your invoices.