There should be a proof marking of 3 stampings somewhere on the frame. Commonly called the 'Triad'
Most likely under the left grip on a later mfg pistol like this one.
The date code/year of proof is a letter,,letter & number,,or combination of.
Usually w/a (*) above the mark.
The other markings are the particular Spanish proof house and the Spanish AutoPistol Proof mark.
Sometimes a bit hard to read but you can figure them out with a little close looking and maybe a magnifying glass.
Here's a link to the codes from a STAR pistol site (all the same codes).
Some good info on these sometimes confusing proof markings too.
Star Firearms: Dating your Star Pistol with Proofmarks
Nice Astra pistols. Very well made and often over looked.