Try this version:
library(forecast)
#> Registered S3 method overwritten by 'quantmod':
#> method from
#> as.zoo.data.frame zoo
sales <- c(291,277,220,260,213,245,156,216,245,270,324,328,320,295,256,264,249,255,233,206,293,270,281,340,348,320,261,279,229,312,195,246,282,300,318,363,387,365,312,292,240,325,232,301,363,351,386,398,414,410,337,354,351,344,253,281,400,387,475,497,485,444,405,445,353,416,308,333,460,449,530,586,492,601,466,426,435,353,292,381,374,440,527,546,562,526,500,479,424,444,376,376,482,449,473,560,670,613,600,577,500,557,427,403,559,520,535,646,684,640,611,570,487)
sales <- ts(sales, start = 2012, frequency = 12)
autoplot(sales)

mod <- Arima(sales, order=c(0,0,3), seasonal = c(0,1,1))
autoplot(mod)
