For the purpose of identification, payment service providers rely on qualified certificates for website authentication. The certificate must be a valid QWac eIDAS certificate respecting the ETSI TS 119 495 technical specification defining the roles granted to the certificate owner:
ETSI TS 119 495: Electronic Signatures and Infrastructures (ESI); Sector Specific Requirements; Qualified Certificate Profiles and TSP Policy Requirements under the payment services Directive (EU) 2015/2366 https://www.etsi.org/deliver/etsi_ts/119400_119499/119495/01.02.01_60/ts_119495v010201p.pdf