When you sign documents you can fill missing content in the document using the stamping tool. Through this tool, you can add name, date, or any missing information. To use the stamping tool click on its icon at the top right corner of the PDF view (shown in the image below).
You can add a general block to add any required information by clicking the Add button (e.g., Date). To add the name of the logged in user, click Add Name. Drag the added block to the location where you need to fill the missing information. The block can also be re-sized and you can change font type and size using the appropriate buttons. For example, in the displayed figure, any added annotation will have font type Helvetica and size 10.
To save the added annotations click the Save button. You can remove one annotation or all un-saved annotations by clicking Remove and Remove All buttons. Note that, once the annotation is saved it cannot be removed.