How to use Percentage field to know the progress of application?
Is there any alternate Progress Bar available for this feature?
You can add a Percentage Indicator to your form that looks like this:
You can customize the look of this by editing the applied Percentage Indicator shared style or creating and applying your own.
It is not a reliable practice to determine percentage complete automatically based on number of mandatory fields completed because dynamic forms often have many questions added and removed from the form based on visibility rules.
Instead you can add a simple business rule to update the percentage complete based on how many pages you've completed. You can do this by adding a Page Change rule to the Page Controller component (usually called Content)
data.percentageIndicator = Math.round(item.$Pages.viewIndex / item.$Pages.visiblePageCount * 100)