Hello,
We are not responsible for the third-party code, sorry, https://themeforest.net/page/item_support_policy
Are you trying to edit PHP files via WP Dashboard? Use FTP for these purposes because in case you make any error you’ll be locked out and won’t be able to change anything back without FTP. So, it would be better to use FTP from start.
Besides, I hope that you make all the changes in the child theme files. Don’t edit any parent theme files because you will lose our changes after the theme update.
Regards