Are you sure you want to go to an external site to donate a monetary value?
WARNING: Some countries laws may supersede the payment processors policy such as the GDPR and PayPal. While it is highly appreciated to donate, please check with your countries privacy and identity laws regarding privacy of information first. Use at your utmost discretion.
Re: @look997:
Could use setInterval and check if the element exists before continuing
Re: @select:
You could have every page run a hidden dummy iframe of a non existent domain and then every page can use that domain for storing cookies, sessions, GM values etc.