How do I create a categorical bar chart using ggplot2?

I want to create a bar chart such that the x-axis contains the different engine_type and the y-axis contains the count. Data frame (DEU_2001_df) below:

   Year engine_type                count
1  2001 petrol_number           2185247 
2  2001 diesel_gas_number       1155300 
3  2001 full_mild_hybrid_number     606.
4  2001 plugin_hybrid_number          0 
5  2001 battery_electric_number      56 

When using the following line:

ggplot(DEU_2001_df, mapping = aes(x = 'engine_type', y = 'count')) +
  geom_bar(stat = "identity")

I get this plot:

Steps taken as above.

>Solution :

Use variable name without inverted commas:

engine %>% ggplot(aes(x = engine_type, y = count)) + geom_bar(stat = 'identity')