From N332.

Reminder from Spanish Government

Remember that if you are going to come to Spain by plane, you have to meet a series of requirements to enter our country. The goal is to minimize risks and reduce the spread of the virus:

First, you must fill in the Health Control Form: Here
In addition, if you travel from a COVID19 risk country or area, you must present a negative PCR or TMA, carried out within 72 hours prior to arrival: Christmas Campaign PDF
Source: Face book page