The best way to create the primary key is to define it as part of creating a table. In the example below, there are two options: one using UUIDs and another using integers as primary keys (the latter is commented out). In both cases the primary key is set to auto-generate a key when a record is inserted into the table.
CREATE TABLE public."Table" (
"id" uuid PRIMARY KEY DEFAULT gen_random_uuid(),
--id serial PRIMARY KEY,
"description" text,
"is_published" boolean );