EBU Single Rulebook Q&A 6 August 2019 2019_4855 Application of the strong customer authentication (SCA) in case of refund

Does a refund, which is considered as an electronic payment transaction, be subject to strong customer authentication (SCA)? Does a merchant that initiates a refund request be considered as a payer? If so, does a Payment service provider (PSP), that holds the payment account of a Merchant, have to set up SCA each time his Merchant is doing a refund from its payment account?