Facing too much loading time to redirect after form submission


This is regarding my website dlp.shikharclasses.in

The website is using premium "SEO WP: Online Marketing, SEO, Social Media Agency" theme which comes with Ninja Forms plugin and Ninja Forms for PayPal add-on.

I created the form using above plugin and extension. Now I wanted to redirect the page to a payment page after submission of the form.

Everything is working fine right now.

My only concern is that after someone hits the submit button, it takes too long to redirect them to the payment page. Which is why some people cancel the payment. Is there any way I can reduce this time?

Thank you,