Changing legend title in ggpattern R

So I am trying to visualize my data in R using the ggpattern package. The problem is that I can't seem to edit the legend's title using the guides function. Before I go further into that, let me show the data

     tag Center  n n_tag      persen
1  lisan     же 11  2142 0.005135387
2 medrus     же  6  2588 0.002318393
3 medsos     же 14  2778 0.005039597
4  puisi     же 15  2622 0.005720824
5  lisan     ну 39  2142 0.018207283
6  puisi     ну 13  2622 0.004958047

And this is the visualization, using the ggpattern package:

As you can see, the title for the legend is currently "Center". I want to change it into "Legenda".

So far, this is the code that I have tried of using, but to no avail:

judul <- paste("Sebaran leksikon", kata_difilter, "\n", "dalam Korpus Nasional Rusia") 
subjudul <- paste("Jumlah token: ", ftj)
viz_akhir <- ggplot(df_viz, aes(tag, persen, fill=Center)) +
  geom_bar_pattern(stat="identity",
                   position=position_dodge(),
                   pattern_color = NA,
                   pattern_fill = "black",
                   pattern_density = 0.25,
                   pattern_spacing = 0.010,
                   pattern_key_scale_factor = 0.70,
                   aes(pattern=Center)) +
  scale_fill_grey(start = 0, end = .9) + #untuk b&w
  theme_light() +
  labs(title=judul, subtitle=subjudul) +
  xlab("Tag korpus") + ylab("Persentase dalam korpus") +
  guides(pattern=guides_legend(title="Legenda"))
  theme(plot.title=element_text(hjust=0.5, face="bold", size=15),
        plot.subtitle=element_text(hjust=0.5, size=8))
print(viz_akhir)

This is the visualization of that code:

It instead make a new legend in place of changing the legend from the ggpattern visualization.

Anybody knows the solution? Thanks in advance!

You have both the fill and the pattern aesthetic mapped to the same variable, so you can combine the legends simply by giving these aesthetics the same names.

You didn't include kata_difilter or ftj in your question, so the plot is not fully reproducible, but I have recreated a modified version of judul and subjudul so the following code should work for you:

ggplot(df_viz, aes(tag, persen, fill = Center)) +
  geom_bar_pattern(stat = "identity",
                   position = position_dodge(),
                   pattern_color = NA,
                   pattern_fill = "black",
                   pattern_density = 0.25,
                   pattern_spacing = 0.010,
                   pattern_key_scale_factor = 0.70,
                   aes(pattern = Center)) +
  scale_fill_grey(start = 0, end = 0.9) + 
  theme_light() +
  labs(title = judul, 
       subtitle = subjudul,
       x = "Tag korpus", 
       y = "Persentase dalam korpus",
       pattern = "Legenda",
       fill = "Legenda") +
  theme(plot.title    = element_text(hjust = 0.5, face = "bold", size = 15),
        plot.subtitle = element_text(hjust = 0.5, size = 8))