asciidoc-pdf doesnt convert emojis in code blocks

i write a text with asciidoc and when i convert with asciidoc-pdf it doesnt convert the emojis from this code block:

[source,java]
----
  public static void lines() {
    System.out.print("♥♥♥♥♥♥♥♥♥♥");
  }
----

the result in the pdf looks like this:

public static void lines() {
System.out.print("¬¬¬¬¬¬¬¬¬¬");
}

And yes i use a custom theme and set a fallback font too. Here is the yaml theme file:

font:
  catalog:
    PTSerif:
      normal: PTSerif-Regular.ttf
      italic: PTSerif-Italic.ttf
      bold: PTSerif-Bold.ttf
      bold_italic: PTSerif-BoldItalic.ttf
    EmojiFallback: 
      normal: EmojiFallback.ttf
      italic: EmojiFallback.ttf
      bold: EmojiFallback.ttf
      bold_italic: EmojiFallback.ttf
  fallbacks:
  - EmojiFallback
base:
  font-family: PTSerif

I hope you can help me. I am grateful for any help

After a long time i found someone who helped me. And give me these ways to fix it.

The simplest way is to extend the default theme and merging in your additions to the font catalog:

extends: default
font:
  catalog:
    merge: true
    PTSerif:
      normal: PTSerif-Regular.ttf
      italic: PTSerif-Italic.ttf
      bold: PTSerif-Bold.ttf
      bold_italic: PTSerif-BoldItalic.ttf
    EmojiFallback: EmojiFallback.ttf
  fallbacks:
  - EmojiFallback
base:
  font-family: PTSerif

Instead of extending the default theme, you could configure the code blocks to use a TTF monospace font:

font:
  catalog:
    PTSerif:
      normal: PTSerif-Regular.ttf
      italic: PTSerif-Italic.ttf
      bold: PTSerif-Bold.ttf
      bold_italic: PTSerif-BoldItalic.ttf
    PTMono:
      normal: PTMono-Regular.ttf
      italic: PTMono-Italic.ttf
      bold: PTMono-Bold.ttf
      bold_italic: PTMono-BoldItalic.ttf
    EmojiFallback: EmojiFallback.ttf
  fallbacks:
  - EmojiFallback
base:
  font-family: PTSerif
code:
  font-family: PTMono

Finally, Asciidoctor PDF now provides an emoji font, which is configured in the default-with-fallback-font theme. So you could extend that theme instead:

extends: default-with-fallback-font
font:
  catalog:
    merge: true
    PTSerif:
      normal: PTSerif-Regular.ttf
      italic: PTSerif-Italic.ttf
      bold: PTSerif-Bold.ttf
      bold_italic: PTSerif-BoldItalic.ttf
  fallbacks: [M+ 1p Fallback, Noto Emoji]
base:
  font-family: PTSerif