Open the PDF in a PDF editor or a browser that supports form filling
Select the text tool or fill-and-sign tool
Click where you want to type
Enter your text
Save the PDF
If the PDF is not editable, convert it to an editable format or use an annotation tool
On mobile, open the PDF in a PDF app and use the edit or fill option
If needed, print the PDF, fill it out by hand, and scan it back into a PDF