Installation problems for Rmarkdown in version 4.0.5 of R

Question

I am having problems installing rmarkedown in version 4.0.5 of R. I first tried the installation going in files -> rmakedown. But when I click Knit to generate the document, I get the following error message:

Error in (function (file = if (onefile) "Rplots.pdf" else "Rplot%03d.pdf",  : cannot open file 'Meu-primeiro-R-markedown_files/figure-latex/pressure-1.pdf'
Calls: <Anonymous> ... in_base_dir -> in_dir -> plot2dev -> do.call -> <Anonymous>

Moreover:

Warning message:
In has_crop_tools() : 
Tool(s) not installed or not in PATH: pdfcrop, ghostcript
-> As a result, figure cropping will be disabled.
Execução interrompida

Someone had this problem and can help me ?