If you need a simple sitemap creator you can download here. It is a free lightweight yet powerful sitemap creator which can build HTML and Google Sitemaps compatible XML sitemap .
Some features of Simple Sitemap Creator
1. Free and Lightweight
2. Easy to use
3. Supports HTTPS
4. Produces HTML, Google compatible XML and CSV
5. Portable
6. Customisable useragent string
7. Standalone, All widnows supported
Instructions to use: 1. Download and unzip the folder named simplesitemapcreator-1.3.3
2. Click on simplesitemapcreator applicatin icon
3. Put your site url on the text box
4. Select HTML/XML/CSV/List
5. Save file to your local disk and upload on google search console