TradeGecko's Payment Method is mapped with WooCommerce Payment Gateway. It is not case-sensitive, and dashes/underscores will be replaced by spaces for matching. For example, if the Payment Method in TradeGecko is "Credit Card", a Payment Gateway of "credit-card" or "credit card" or "Credit Card" would still match.
First, you need to know the Payment Gateway Names in WooCommerce. To do this, login to WooCommerce Admin > Settings > Checkout > Payment Gateways. See below.
Second, make sure the Payment Gateway names exist in TradeGecko. If not, you have to create this Payment Method in order for us to capture the Payment Type. You can find this under TradeGecko Settings > Configuration > Payment Methods > New Payment Method.
And the Invoice will sync to XERO/QuickBooks with its Default Payment Ledger account.