diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index ccfe1e6..df1cf4c 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -9,7 +9,7 @@ version: 2
 build:
   os: ubuntu-20.04
   tools:
-    python: "3.8"
+    python: "3.10"
     # You can also specify other tool versions:
     # nodejs: "16"
     # rust: "1.55"
diff --git a/README.md b/README.md
index 37e614a..a41833d 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
 
 <p align="center">
   <img alt="GitHub Actions Badge" src="https://github.com/UTokyo-FieldPhenomics-Lab/EasyIDP/actions/workflows/pytest.yml/badge.svg?style=plastic">
-  <img alt="GitHub code size in bytes" src="https://img.shields.io/tokei/lines/github/UTokyo-FieldPhenomics-Lab/EasyIDP?style=plastic">
+  <img alt="PyPI - Python Version" src="https://img.shields.io/pypi/pyversions/easyidp">
   <img alt="GitHub" src="https://img.shields.io/github/license/UTokyo-FieldPhenomics-Lab/EasyIDP?style=plastic">
   <img alt="GitHub top language" src="https://img.shields.io/github/languages/top/UTokyo-FieldPhenomics-Lab/EasyIDP?style=plastic">
   <img alt="GitHub Downloads" src="https://img.shields.io/github/downloads/UTokyo-FieldPhenomics-Lab/EasyIDP/total?label=github%20downloads&style=plastic">
diff --git a/docs/index.rst b/docs/index.rst
index 002c80a..d699686 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -18,8 +18,8 @@ EasyIDP (Easy Intermediate Data Processor) is a handy tool for dealing with regi
 
 .. _Sphinx: http://sphinx-doc.org
 
-.. image:: https://img.shields.io/tokei/lines/github/UTokyo-FieldPhenomics-Lab/EasyIDP?style=plastic
-   :alt: GitHub code size in bytes
+.. image:: https://img.shields.io/pypi/pyversions/easyidp
+   :alt: PyPI - Python Version
 
 .. image:: https://img.shields.io/github/license/UTokyo-FieldPhenomics-Lab/EasyIDP?style=plastic
    :alt: GitHub
diff --git a/easyidp/shp.py b/easyidp/shp.py
index bbfdea7..9ada994 100644
--- a/easyidp/shp.py
+++ b/easyidp/shp.py
@@ -416,7 +416,7 @@ def _find_name_related_int_id(shp_fields, name_field):
     
     return field_id
 
-def _get_plot_name_template(roi_fields: dict, field_id:int | list, include_title:bool):
+def _get_plot_name_template(roi_fields, field_id, include_title):
     """
     Parameters
     ----------
diff --git a/setup.py b/setup.py
index 09a70af..d8d5ec0 100644
--- a/setup.py
+++ b/setup.py
@@ -52,9 +52,10 @@ def parse_requirements_file(filename):
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3 :: Only",
     ],
-    python_requires='>=3.6, <4',
+    python_requires='>=3.7, <4',
     project_urls={
         'Documentation': 'https://easyidp.readthedocs.io/en/latest/',
         'Source': 'https://github.com/UTokyo-FieldPhenomics-Lab/EasyIDP',