src/Config/ShopCapabilities.php
public function getSupportedInvoiceSourceTypes()
    {
        return array(
            Source::Order => ucfirst($this->t(Source::Order)),
            Source::CreditNote => ucfirst($this->t(Source::CreditNote)),
        );
    }
public function getSupportedInvoiceSourceTypes()
    {
        return array(
            Source::Order => ucfirst($this->t(Source::Order)),
            Source::CreditNote => ucfirst($this->t(Source::CreditNote)),
        );
    }
public function getSupportedInvoiceSourceTypes ( ) { return array ( Source :: Order => ucfirst ( $ this -> t ( Source :: Order ) ) , Source :: CreditNote => ucfirst ( $ this -> t ( Source :: CreditNote ) ) , ) ; }
Returns a list of invoice source types supported by this shop.

The default implementation returns order and credit note. Override if the
specific shop does not support credit notes (or supports other types).

@return string[]
The list of supported invoice source types. The keys are the internal
{@see \Siel\Acumulus\Invoice\Source} constants, the values are
translated labels.
Returns a list of invoice source types supported by this shop .