Avoid Masking URL and Embedding Form
Normally, when someone submits the registration form, we use a cookie to track that registration as they navigate through the site. When they are on our website, the cookie is seen as a 1st-party cookie and is usually accepted. When the URL is masked or when the registration form is embedded on your website (such as, in an iframe), the cookie is a 3rd party cookie. By default, Safari blocks 3rd party cookies. When someone registers using Safari (or any browser with 3rd party cookies blocked) the cookie is blocked and registration fails.
The easiest solutions are:
Make sure the registration form URL is showing on the top of the page. You can do this by logging into the domain for your URL and changing the setting to forwarding without masking.
Avoid embedding the registration form on your website (such as, in an iframe).
If you do embed the registration form on your website, you might consider adding a Safari-specific link to your event web page that directs Safari users to the FundEasy site. Or you can instruct Safari users to make sure that 3rd party cookies are allowed. These articles from Apple have more information on changing settings in Safari.
https://support.apple.com/guide/safari/manage-cookies-and-website-data-sfri11471/mac
https://support.apple.com/en-us/HT201265
Use the Actual Registration Form Link
You'll also want to make sure that you provided your participants with the correct link to your registration form. Copying the URL for the Registration Form page in Event Setup or from the preview of the Registration Form in a new tab will give a URL that looks something like these:
In both cases, you'll see the word "preview" at the end of the URL, indicating that it is simply a preview of the form. The form preview will not register anyone to the event.
To access the actual registration form, you can send participants to your Event Web Page, where they can access the registration form for the event. To find the Event Web Page link, click the Promote Event icon in the bottom left corner of your event. Or, to find the direct registration form link, click the Promote Event icon in the bottom left corner and then click the blue link that says Advanced Link Options.