Please note the current set available here (currently Version 3.2) is copyrighted but can be used without cost under the terms of the LGPL 3.0 open source license referenced in the required attrition text.
Per the license, it is required to provide the standardized attribution text in a publicly visible fashion, either as part of your product or on a publicly accessible webpage.
Vectorized Playing Cards 3.2
Copyright 2011,2021 – Chris Aguilar – email@example.com
Licensed under: LGPL 3.0 – https://www.gnu.org/licenses/lgpl-3.0.html
More information can be found via the FAQ (Frequently Asked Questions Page)