www.mmmm.es/en/blogs-lawyers/business-tax-spain/vat-on-bitcoin-related-services/
www.engage.hoganlovells.com/knowledgeservices/news/online-intermediaries-are-obliged-to-collect-spanish-vat-on-sales-of-nfts-through-their-marketplaces
See also:
bit.ly/3MhM0gl