Shapiro-Wilk normality test

See the FAQ: How to do a minimal reproducible example reprex for beginners.

res_aov <- aov(Sepal.Length ~ Species, data = iris)
shapiro.test(res_aov$residuals)
#> 
#>  Shapiro-Wilk normality test
#> 
#> data:  res_aov$residuals
#> W = 0.9879, p-value = 0.2189