To write Punjabi in Adobe Illustrator, you need to ensure that the Punjabi font is installed on your computer. Here are the steps to write in Punjabi:

1. Open Adobe Illustrator on your computer.
2. Create a new document or open an existing one.
3. Select the Text tool from the toolbar on the left side of the screen.
4. Click on the artboard to create a text box.
5. In the Character panel (Window > Type > Character), choose a Punjabi font from the font dropdown menu. If you don’t see the Punjabi font listed, make sure it is installed on your computer.
6. Start typing in Punjabi using the keyboard layout that corresponds to the Punjabi script.
7. Adjust the font size, color, and other formatting options as desired.
8. You can also use the Paragraph panel (Window > Type > Paragraph) to adjust the alignment and spacing of your Punjabi text.
9. To edit the Punjabi text further, simply select the text box and make the necessary changes.

Remember to have the Punjabi font installed on your computer for it to be available in Adobe Illustrator.