Using r-exams to include circuitikz package

I want to generate electric circuit picture using circuitikz packages and r-exams in R markdown. I already include circuitikz package in header-includes, it's successful when using `knit` But when executing `exams2pdf` , here is the error i get,, ``` LaTeX Error: Environment tikzpicture undefined. ``` Executing `exam2moodle` or `exam2html` get no error, but it did not include the circuit image Any alternative solution?