To achieve this, let's use the “setFormFieldValues” step in the process definition. 

Let’s use the form definition “TestFormFile,” which is as follows:

Let’s use the process definition “TestFormFileDef,” which appears as follows:

Let's move the “setFormFieldValues” step to the designer and connect it to the process's last step. The red alert sign shows that the step property configuration is incomplete. The goal is to set or modify the Form field value from within the process.

Click the “setFormFieldValues” step to set up the Settings properties. Enter the variable reference that contains the Form instance ID. Click the button to configure the field mapping, and a pop-up window will open. Select the “Comments” Form field and enter a value. Click the Save button to finalise the configuration.  

Save the changes to the step and the process definition.   

Let’s create and run a new process instance to see the change to the Form instance name. 

Then navigate to the Engage > Tasks page, as shown below. Select the Instances search filter and choose the process instance from the drop-down list. The incomplete task assigned to the user appears below. You can also search for the task using the Search textbox. Click the task to open it.

When filling out the Form, give the value of “Admin-Simpson” for the entire name field. When the Form is completed, submit it. Note: The Comments textbox is left empty as it's read-only, and this field value is set within the process using the “setFormFieldValues” step. 

The following is the executed path for the process instance. To inform you, the process instance is complete. 

You can navigate to the Form instances to see the list of Form entries. The list should include a Form instance named “Admin-Simpson” because that was the value entered in the Form for the “txtFullName” field. Select this form instance and click the View > Render menu option to see the Form values. 

The Form instance is rendered on the new page, and as observed, the Comments field value is set during the process using the “setFormFieldValues” step.