Error message when click "donate now"

Hi,

First of all thanks for your great plugin!

I am facing a problem with the plugin and I don’t know how to proceed.

when a person filled in the form and press donate now, it displayed the following message:
Fatal error: Call to undefined function edd_get_option() in /home/www/8cfafb71bbc8f19074843b877619cc6a/web/eeig-wp1/wp-content/plugins/give/includes/gateways/paypal-standard.php on line 530

Here is the URL of the page : http://eeig.ch/faire-un-don/

I am not able to delete any pending test transaction in the transactions, a message displayed Access denied!

How can I solved these?
Thanks for your help.

https://ww.wp.xz.cn/plugins/give/