How to create tables in Postgre with fields not null?

Question

good morning gentlemen,

I made my attempt to create my Postgre table this way:

CREATE TABLE categoria (
    codigo BIGSERIAL,
    nome VARCHAR(50) NOT NULL,
    PRIMARY KEY(codigo)
); 

Despite the countryside name be as not null it is allowing it to be entered null as you can see below;

Image 1

proof of insertion:

field description:

Could it be that something was missing in the construction of the table for it to effect the not null in the field name?