code: public static String replaceAllEmojis(String str, final String replacementString) {
      EmojiParser.EmojiTransformer emojiTransformer = new EmojiParser.EmojiTransformer() {
        public String transform(EmojiParser.UnicodeCandidate unicodeCandidate) {
          return replacementString;
        }
      };
  
      return parseFromUnicode(str, emojiTransformer);
    }
docs: Replace all emojis with character
  
  @param str the string to process
  @param replacementString replacement the string that will replace all the emojis
  @return the string with replaced character