https://www.reuters.com/business/media-telecom/us-impose-100...

You are correct on this point, the correct phrasing would be “announces intent to impose” not “imposes”. You, however, proceed to make a similar error:

> Second, the President cannot invent a new law and can only apply authorities given to him by existing laws

This sentence misuses “can” (which expressed capability) in place of “may" (which expresses permission).

The President can act outside of authorities given by existing laws, and regularly does. The President may not, (under the Constitution and laws, consistent with his oath of office, etc., do so), but nothing actually prevents or, to date, imposes meaningful consequences after the fact, when he does, making that lack of permission more of an issue in abstract theory than concrete practice.

Did this matter to Trump by all the things he did before?

You are confusing cannot with isn’t allowed to.