Postgres SQL-TG_ARGV within query

I’m trying to do a trigger that will verify if a record exists in the table passed as argument. I’m doing it as a laravel migration but nervertheless the SQL should be perceptible

DB::unprepared('
        CREATE OR REPLACE FUNCTION insert_or_update_lojas() RETURNS trigger AS $insert_or_update_lojas$
        DECLARE
            store TEXT := TG_ARGV[0]::TEXT;
    BEGIN
        -- Check if product exists
        IF 
            EXISTS (SELECT 1 FROM TG_ARGV[0]::TEXT WHERE ean = NEW.ean)
        THEN
            UPDATE store SET price_form_factor=NEW.price_form_factor, price_unit=NEW.price_unit WHERE ean=NEW.ean;
            RETURN NULL;
        END IF;
        
        RETURN NEW;
    END;
    $insert_or_update_lojas$ LANGUAGE plpgsql;');



DB::unprepared('
    CREATE TRIGGER insert_or_update_continente BEFORE INSERT ON continente FOR EACH ROW EXECUTE PROCEDURE insert_or_update_lojas('continente');');

Right now I’m getting

relation "store" does not exist LINE 1: SELECT EXISTS (SELECT 1 FROM store WHERE ean = NEW.ean) ^ QUERY: SELECT EXISTS (SELECT 1 FROM store WHERE ean = NEW.ean) CONTEXT: PL/pgSQL function insert_or_update_lojas() line 6 at IF

EDIT:
After googling for the past day i slightly changed the if statement. IF EXECUTE format('EXISTS SELECT 1 FROM %s WHERE ean = NEW.ean', store) THEN EXECUTE ('UPDATE store SET price_form_factor=NEW.price_form_factor, price_unit=NEW.price_unit WHERE ean=NEW.ean'); RETURN NULL; END IF;

I know the format() works. However when I do EXECUTE format() I get the following error:

SQLSTATE[42601]: Syntax error: 7 ERROR:  syntax error at or near "("
LINE 8:                 
EXECUTE format('EXISTS SELECT 1 FROM %s WHER...
                                      ^ 
(SQL: 
            CREATE OR REPLACE FUNCTION insert_or_update_lojas() RETURNS trigger AS $insert_or_update_lojas$
            DECLARE
                store TEXT := quote_ident(TG_ARGV[0]);
        BEGIN
            -- Check if product exists
            IF 
                EXECUTE format('EXISTS SELECT 1 FROM %s WHERE ean = NEW.ean', store)
            THEN
                EXECUTE ('UPDATE store SET price_form_factor=NEW.price_form_factor, price_unit=NEW.price_unit WHERE ean=NEW.ean');
                RETURN NULL;
            END IF;