Conditions for refund or change of flight dates due to the flight cancellation through a pandemic:
https://youtu.be/eV11yGNpe0M
and
The European Commission has obliged airlines to refund for the tickets on canceled flights!
https://youtu.be/XW7uceS_H3U
There is no law or regulation that explicitly states that you are entitled to a refund of those taxes (i.e. explicitly stating “if you don’t fly you can get a refund of those taxes”). However those taxes are imposed by various authorities on the basis that you will be flying, and if you are not, most of those taxes no longer have a basis, and you are entitled to claim a refund, so it’s more an indirect thing.
Some airlines explicitly state you can claim a refund on their site or in their conditions of carriage, which is often used to set limits on your claims (such as claiming within 7 days or having to use a specific form), or provide a way to make the claim online. See for instance:
It does not seem to be the case for TAP, so you will just have to contact them.
Note that you can reference Article 4.2 of their Conditions of Carriage, which covers this, even though not explicitly:
Similarly, in the event any tax and/or fee and/or charge which you have paid to us is abolished or reduced such that it no longer applies to you or a lesser amount is due, you will be entitled to claim a refund.
Credit:stackoverflow.com‘