How to use sliders in plotly to select a and b values for a beta distribution

I'm trying to draw a beta distribution in R using plotly. The goal is to get 2 sliders to select the a and b parameters of the function to see what is the effect of modifying one at the time.

I'm able to draw the graph and the sliders, but the only issue is that the sliders are actually not connected to the graph. I'm not seeing clear anymore. Perhaps it's just a little detail in the code, but it just doesn't want to connect the sliders to the "a" and "b" of the dbeta(x,a,b) in R.

# Load the library
library(plotly)

# Define the squences of X and the different values that a and b will take 
x = seq(from = 0, to =1, by = 0.01)
# sequence for a and b  
seqi = seq(0,5,by = .26)

# Define a and b for beta distributions 
all_a <- list()
for (i in 1:length(seqi)) { 
  all_a[[i]] <- list(method = "relayout",
                       args = list(list(a = seqi[i])),
                       label = seqi[i])
}

all_b <- list()
for (i in 1:length(seqi)) { 
  all_b[[i]] <- list(method = "relayout",
                     args = list(list(b = seqi[i])),
                     label = seqi[i])
}

# Define the steps 
steps <- list()

# Make empty plot 
fig <- plot_ly()

# Empty list of available data 
aval <- list()
for(step in 1:length(seqi)){
  aval[[step]] <-list(visible = FALSE,
                      name = paste0('Density = ', step),
                      x=x,
                      y=dbeta(x,step,step)) # This is the beta density curve in R 
}
aval[3][[1]]$visible = TRUE

# Draw the actual beta distribution 
for (i in 1:length(seqi)) {
  fig <- add_lines(p = fig,
                   x=aval[i][[1]]$x,  
                   y=aval[i][[1]]$y, 
                   visible = aval[i][[1]]$visible, 
                   name = aval[i][[1]]$name, 
                   type = 'scatter', mode = 'lines', hoverinfo = 'name', 
                   line=list(color='00CED1'), 
                   showlegend = FALSE)
  
  step <- list(args = list('visible', rep(FALSE, length(aval))),
               method = 'restyle')
  step$args[[2]][i] = TRUE  
  steps[[i]] = step 
}  

# Show the 2 slides of a and b to modify the average of the distribution 
fig <- fig %>% layout(sliders = list(
                        
                        list(
                          active = (length(x)-1), 
                          currentvalue = list(prefix = "a: "), 
                          pad = list(t = 20), 
                          
                          steps = all_a),
                        
                        list(
                          active = (length(x)-1), 
                          currentvalue = list(prefix = "b: "), 
                          pad = list(t = 100), 
                          
                          steps = all_b)))
# Show the figure  
fig

This gives this image:

But whenever I change the sliders, nothing happens...