Why is BigQuery Sandbox saying its ERROR: Expected keyword AS but got "(" at [1:17]

Question

Is this an issue with BigQuery. I was following along with this Youtube video and for some reason this code will not work.

WITH pop_vs_vac (continent, location, DATE, population, new_vaccinations, rolling_people_vaccinated)
AS 
(
    SELECT 
        dea.continent, dea.location, dea.DATE, dea.population, 
        vac.new_vaccinations, 
        SUM(CAST(vac.new_vaccinations AS INT)) 
            OVER (PARTITION BY dea.location ORDER BY dea.location, dea.DATE) AS rolling_people_vaccinated  -- (rolling_people_vaccinated/population)* 100
    FROM 
        [gg-analytics-404715.Portfolio_Covid.Covid_Deaths] AS dea
    JOIN 
        [gg-analytics-404715.Portfolio_Covid.Covid_vaccinations] AS vac
            ON dea.location = vac.location
            AND dea.DATE = vac.DATE
    WHERE 
        dea.continent IS NOT NULL
        --- order by 1, 2, 3
)
SELECT *
FROM pop_vs_vac