Hi healermax,
Here are the instructions to install PlayOnLinux on Chromebook.
Step 1. Enable Linux Beta.
Go to Launcher and open settings. Click on Linux Beta. Click setup.
Step 2. Download the deb file for playonlinux.
Visit https://www.playonlinux.com/script_files/PlayOnLinux/4.3.4/PlayOnLinux_4.3.4.deb to begin download
Step 3. Install POL.
Open the Chrome OS my files app. Double click or right click and select Install with Linux (Beta).
Click Install then click ok. Wait for install. Use terminal to launch POL (command: playonlinux) or use the App Launcher.
If you still have further problems, please feel free to ask me. I am a fairly experienced user with the Crostini compactability layer.