Hi @kiyan_04_sa. The creator of the "Sduino STM8 plain C core (non-C++)" boards platform made a mistake while creating one of the archive files that are installed by the Arduino IDE Boards Manager when installing this platform. That is the cause of the error:
Unfortunately, even though the problem has been reported to them repeatedly over the last four years, they have not corrected it.
I think the most simple solution will be to use Arduino IDE 1.8.19 to install the platform. Arduino IDE 1.x was more resilient to this type of invalid archive structure and so is able to install the platform even though it is technically invalid. Arduino IDE 2.x recognizes the platform installations made through Arduino IDE 1.x, so once you install the platform via Arduino IDE 1.x you can immediately switch back to using Arduino IDE 2.3.2 again.
I'll provide instructions you can follow to do that:
Select File > Quit from the Arduino IDE menus.
All Arduino IDE windows will close.
Under the "Legacy IDE (1.8.X)" section of the page, click the "Windows ZIP file" link.
The "Download Arduino IDE & support its progress" page will open.
If you would like to contribute to Arduino's work on open source software, you can make a donation. Otherwise click the "JUST DOWNLOAD" link on that page.
The "Stay in the Loop: Join Our Newsletter! page will open.
If you would like to sign up for the Arduino newsletter, you can do that. Otherwise click the "JUST DOWNLOAD" link on that page.
Your browser will start a file download.
Wait for the download to finish.
Extract the downloaded file to any convenient location on your computer.
Run the file arduino.exe from the downloaded folder.
Arduino IDE 1.8.19 will start.
Select File > Preferences... (or Arduino > Settings... for macOS users) from the Arduino IDE 1.8.19 menus.
The "Preferences" dialog will open.
Enter the following URL into the "Additional Boards Manager URLs" field of the "Preferences" dialog:
Click the "OK" button in the "Preferences" dialog.
The "Preferences" dialog will close.
Select Tools > Board > Boards Manager... from the Arduino IDE menus.
The "Boards Manager" dialog will open.
Wait for the updates to finish, as shown by the messages printed at the bottom of the "Boards Manager" dialog.
Scroll down through the list of boards platforms until you find the "Sduino STM8 plain C core (non-C++)" entry. Click on it.
Some buttons will appear on the entry.
Click the "Install" button on the "Sduino STM8 plain C core (non-C++)" entry.
Wait for the installation to finish.
Click the "Close" button on the "Boards Manager" dialog.
The "Boards Manager" dialog will close.
Select File > Quit from the Arduino IDE menus.
Arduino IDE 1.8.19 will close.
Start Arduino IDE 2.3.2.
You should now see the boards of the installed platform under the Arduino IDE Tools > Board > Sduino STM8 plain C core (non-C++) menu.
You can now delete the folder containing Arduino IDE 1.8.19 you extracted at step (7) in the instructions as it is no longer required.