There are two main reasons why the Instant Pot is not easily found here:
1 - stovetop pressure cookers are cheap, readily available, standard bits of kit in most homes in mainland Europe (where there was never the fear of them that has existed in other places), starting at well under half the price of an Instant Pot - and you can do pretty much all the other things an Instant Pot can in one of them (just without the automation);
2 - the Bimby (which is a Thermomix in other European countries), whilst massively more expensive, has a widespread cult following, and can do loads of things (overlapping with, but not completely covering, the Instant Pot - it doesn't pressure cook, because see point 1), in the same small space. It's made in France/Germany, and has evolved since the 60s, so is "the" brand for multi appliances (and various copies exist).
None of this is to denigrate the Instant Pot! It just doesn't seem to have found much of a market here. Worten have a Crockpot version of the Instant Pot on their site (but showing out of stock online), the CSC051X, for a better price than importing an Instant Pot.
However, as Astrid mentions, you can get Instant Pots from Amazon Spain. If you use a third party seller, make sure they are EU based seller (if not Amazon itself) - non European sellers may not sell the EU version (in terms of voltage); and imports from the UK or elsewhere may run you up huge additional costs in tax/duty/fees.