There are two ways to reach the EURO 2020:
UEFA Nations League: all you need to know (from http://www.uefa.com/uefanationsleague/news/newsid=2079553.html#/):
League C
Pot 1: Hungary, Romania, Scotland, Slovenia
Pot 2: Greece, Serbia, Albania, Norway
Pot 3: Montenegro, Israel, Bulgaria, Finland
Pot 4: Cyprus, Estonia, Lithuania
Teams will be split into one group of three (containing teams from Pots 1, 2 and 3 only) and three groups of four.
Due to winter venue restrictions, a group can contain a maximum of two of these teams: Norway, Finland, Estonia, Lithuania.
The four group winners are promoted to League B, with the four sides that finish bottom relegated to League D for the 2020 edition.
The top four ranked teams that do not qualify for UEFA EURO 2020 will enter a play-off in March 2020, with one finals place on offer.