For now my plan is to use Cloudflare Turnstille, it’s also relatively easy to use in Wappler. They have a Data Processing Addendum that should make it GDPR-compliant:
Cloudflare’s Data Processing Addendum is incorporated into both our Self-Serve Subscription Agreement and our standard Enterprise Subscription Terms of Service. For customers with negotiated Enterprise Agreements, you can obtain a copy of your Data Processing Addendum by contacting your Account representative.