Adding Text to a Custom Field Box

I am trying to create a custom Field box for Bank Details so they show at the bottom of Sales Invoices. When I set it up the details I put in are below the white box but I want the details in the white box. Any help?

See the guide:
https://www.manager.io/guides?footers
and
https://www.manager.io/guides?form-defaults

" To automatically select one or more footers for new transactions, utilize the Form Defaults feature. See Form Defaults for more information.".

So you have to enter the desired text in the footer field of the default form.
After that, the content of the custom field is visible on all sales invoices.

Many Thanks. Works perfect…