Influencers are required to disclose ads in most places.

In theory, but it takes less than a minute on Instagram to find dozens of "influencers" violating this rule.

In Spain (and I believe the EU), it’s required to indicate it.

Can confirm in the Netherlands also. I'm not an influencer so I don't know exactly, but a few years ago there was either a crackdown, an expansion of the rules, or at least a big media campaign by the government to make the influences that focus on a Dutch audience aware of the rules surrounding promoted content

Influencers have been successfully sued in Europe due to covert advertising.