ConditionalPanel does not work as expected - r

Question

I'm making an app for some tax calculations and want to show a sliderInput based on another user input (input$use_fthbi). Here's my code:
checkboxInput(
inputId = 'use_fthbi',
label = 'Use First-time Home Buyer Incentive?',
value = F
),
conditionalPanel(
condition = "input.use_fthbi == 'true'",
sliderInput(
inputId = 'fthbi',
label = 'FTHBI Percent',
min = 0,
max = 10,
value = 5,
post = '%'
)
)
I expect to see the sliderInput appear only when use_fthbi is selected but it shows up regardless. Checking or unchecking the input has no impact on the UI.
I've tried spelling true as True or even T both with and without quotes around it but with no change to the UI. Following the example here: https://shiny.rstudio.com/articles/dynamic-ui.html
I've seen other similar questions on SO but they either relate to updating something using the server or just deal with typos.
EDIT
It appears to work with radiobuttons:
radioButtons(
inputId = 'use_fthbi',
label = 'Use First-time Home Buyer Incentive?',
choices = c('Yes', 'No'),
selected = 'No',
inline = T
),
conditionalPanel(
condition = "input.use_fthbi == 'Yes'",
sliderInput(
inputId = 'fthbi',
label = 'FTHBI Percent',
min = 0,
max = 10,
value = 5,
post = '%'
)
)

Answer 1

You were close. The trick is to not use any quotes around true:
checkboxInput(
inputId = 'use_fthbi',
label = 'Use First-time Home Buyer Incentive?',
value = F
),
conditionalPanel(
condition = "input.use_fthbi == true",
sliderInput(
inputId = 'fthbi',
label = 'FTHBI Percent',
min = 0,
max = 10,
value = 5,
post = '%'
)
)
This works for me with shiny 1.5.0 and R 4.0.2