How to integrate paypal in autoride theme booking checkout page?

I am getting error while pay with paypal button in autoride theme booking checkout page. I attach pic of error which i am getting. Theme is paid theme from themeforest. Anyone can help please.

Hi @egliimo21,

Please contact the author of your purchased theme, the theme author will assist you.

How to contact an author to get support or for any technical query:

Thanks