To me it looks like an assassin bug (family Reduviidae). They are characterized by their narrow head and "beak", the mouth part also visible on your photo. Example:
That looks promising, and I could be wrong about the family. I'm not sure enough to advise on this one, I suggest try and direct message Felix, he knows a lot about insects in Portugal:
comments (6)
https://www.jungledragon.com/image/44081/rhynocoris_cuspidatus.html
But I have some doubt. There's this mysterious extra "tongue" appendage in your photo, so now I'm not sure anymore. Posted 3 years ago, modified 3 years ago
https://www.jungledragon.com/specie/10998/micrelytra-fossularum.html
I see some similarities. Posted 3 years ago, modified 3 years ago
I agree with Christine’s ID, Micrelytra fossularum, Alydidae.
Nice capture, cheers* Posted 3 years ago