diff --git a/fun_text_processing/README.md b/fun_text_processing/README.md
index 878601b42..3982bed7c 100644
--- a/fun_text_processing/README.md
+++ b/fun_text_processing/README.md
@@ -10,17 +10,32 @@ FunTextProcessing is a Python toolkit for fundamental text processing in ASR inc
 - FunTextProcessing supports inverse text processing (ITN), text processing (TN).
 - FunTextProcessing supports multilingual, 10+ languages for ITN, 5 languages for TN.
 
+#### Installation
+
+Fun Text Processing, specifically (Inverse) Text Normalization, requires Pynini to be installed.
+```
+bash fun_text_processing/install_pynini.sh
+```
 
 ### Example
 #### Inverse Text Processing (ITN)
 Given text inputs, such as speech recognition results, use `fun_text_processing/inverse_text_normalization/inverse_normalize.py` to output ITN results. You may refer to the following example scripts.
 
 ```
-test_file=fun_text_processing/inverse_text_normalization/id/id_itn_test_input.txt
-
-python fun_text_processing/inverse_text_normalization/inverse_normalize.py --input_file $test_file --cache_dir ./itn_model/ --output_file output.txt --language=id
+python fun_text_processing/inverse_text_normalization/inverse_normalize.py --text="ratus dua puluh tiga" --language=id
 ```
 
+Arguments:
+- text - Input text. Should not exceed 500 words.
+- input_file - Input file with lines of input text. Only one of text or input_file is accepted.
+- output_file - Output file to save normalizations. Needed if input_file is specified.
+- language - language id.
+- input_case - Only for text normalization. lower_cased or cased.
+- verbose - Outputs intermediate information.
+- cache_dir - Specifies a cache directory for compiled grammars. If grammars exist, this significantly improves speed.
+- overwrite_cache - Updates grammars in cache.
+- whitelist - TSV file with custom mappings of written text to spoken form.
+
 
 ### Acknowledge
 1. We borrowed a lot of codes from [NeMo](https://github.com/NVIDIA/NeMo).