Adjust or Remove the spam in the admin notice

I appreciate that this is a free plugin, but it would be good to have a bit more transparency about your use of a referral link.
Also by using a referral link for iubenda you might be running afoul of the plugin rules

From https://developer.wordpress.org/plugins/wordpress-org/detailed-plugin-guidelines/
“Advertising within the WordPress dashboard should be avoided, as it is generally ineffective. Users normally only visit settings pages when they’re trying to solve a problem. Making it harder to use a plugin does not generally encourage a good review, and we recommend limiting any ads placed therein. Remember: tracking referrals via those ads is not permitted (see guideline 7) and most third-party systems do not permit back-end advertisements. Abusing the guidelines of an advertising system will result in developers being reported upstream.”

The base url iubenda.refr.cc is from a service called referral candy so it’s quite clear that this is a referral. I’m not sure though how strict they on affiliate links.
I don’t know if there are any GDPR specific issues with using plain referral links but given their services I’d hope the iubenda have produced guidance on correct usage here.