If your object is the Quotation/Sales Order use: ${object.partner_invoice_id.email}

if it's the Invoice use: ${object.partner_id.email}

Hello, I cannot give a screenshot because there is the customer info but I am looking to fill in the recipient email fields with the recipient invoicing from the client company because currently his sends the invoices to the secretary rather than to the accounting invoicing office from my client.

Example current placeholder $ {object.partner_id.id}
wish $ {object.partner_id.envoice_mail or sale_mail etc ...}