The best place for bug reports is the official Project Arrhythmia Discord server[discord.gg], in the dedicated bug reporting channel.
You can also start a new Project Arrhythmia Steam discussion in case you don't have access to the Discord server for whatever reason.

Before reporting, try to look if the issue has already been reported and resolved:

• For Discord go to the bug reporting channel, press Ctrl + F and type in a few words that describe your issue
  
• For Steam use the search feature on the top-right of the Discussions page

If you haven't found anything relevant, you can proceed.

For a good bug report you'll need:

• A good description of your issue
  
• Mention of the version you're playing
  
• Steps to reproduce your issue or description of what you did before the issue occurred
  
• A Project Arrhythmia log file

You're not required to provide everything from this list.
When you think you're all set, you can proceed!

For Discord:

1. Navigate to the bug reporting thread channel[discord.com].
   
2. Press the New Post button located at the top-right of the page.
   
3. In the newly opened section, for the "Title" field: describe your issue in a few words
   
4. For the "Enter a message..." field: write down your bug report.
   
5. Link or attach your .log file or screenshots, if you have any.
   If your log file is over upload size limit, refer to Third Party tools section.
   
6. Choose appropriate post tags, like "Bug", "Game breaking bug", etc.
   
7. Click on Post!

For Steam Discussions:

1. Navigate to the Steam Discussions page.
   
2. Press the Start a New Discussion button located at the top-right of the page
   
3. In the newly opened section, for the "enter a title" field: describe your issue in a few words
   
4. For the "say something" field: write down your bug report
   
5. Link any applicable log files or screenshots. Refer to Third Party tools section
   
6. Click on Post Discussion!

Note that Player.log only logs the current Project Arrhythmia session. If the issue happened in the previous session - use Player-prev.log instead.

Windows:

1. Do the Windows Key + R shortcut
   
2. In the newly opened "Run" window, enter this path and press enter:
   %appdata%/../LocalLow/Vitamin Games/Project Arrhythmia/
3. There it is! Player.log file!

Steam Deck (Linux with Steam Proton):

1. Open your favourite file browser
   
2. Navigate to your PA compatibility folder. Unless you set a custom Steam Library directory, it's this:
   ~/.local/share/Steam/steamapps/compatdata/440310/pfx/drive_c/users/steamuser/AppData/LocalLow/Vitamin\ Games/Project\ Arrhythmia/
3. There it is! Player.log file!

For uploading screenshots you can use Google Drive[drive.google.com], ImgBB[imgbb.com], PostImages[postimages.org].
For uploading log files you can use Google Drive[drive.google.com].