Doesn't seem to work with custom language in a bookdown document

[bayeslearnerold]

`
{r include=FALSE}
knitr::knit_engines$set( pwsh = function ( options ) {
f = tempfile( 'code', '.', fileext = '.ps1' )
writeLines( c(

paste0( '  ', options$code )

), f )
on.exit( unlink( f ), add = TRUE )
cmd = Sys.which( 'pwsh.exe' )
extra = if ( options$eval ) {
args <- paste0( ' ', f )
message( 'running: ', cmd, args )
tryCatch(
system2( cmd, args, stdout = TRUE, stderr = TRUE, env = options$engine.env ),
error = function ( e ) {
if ( !options$error ) stop( e )
'Error in executing pwsh code'
}
)
}
if ( options$results == 'hide' ) extra = NULL
knitr::engine_output( options, options$code, extra )
} )

klippy::klippy('')
`
I added the above and it doesn't seem to work