Hi @Georguel! Welcome to RStudio Community!
As a note, it is extremely hard to help debug error messages when screenshots are posted. While you have managed to get help in this thread, it is likely to decrease your chances of getting the help you are looking for in general. Instead of posting a screenshot, please copy and paste the code and error message and format the pasted code/format as shown below.
Put code that is inline (such as a function name, like mutate or filter) inside of backticks (`mutate`) and chunks of code (including error messages and code copied from the console) can be put between sets of three backticks:
```
example <- foo %>%
filter(a == 1)
```
This process can be done automatically by highlighting your code, either inline or in a chunk, and clicking the </> button on the toolbar of the reply window!
This will help keep our community tidy and help you get the help you are looking for!
For more information, please take a look at the community's FAQ on formating code