Where to change websites settings on Safari, IPadOS 14

I am trying to make a video online on this website https://spark.adobe.com/. And I got this error.

I don’t know how to make the requested change. I cannot find the mentioned path on my iPad. In the Settings>Safari I cannot find Preferences. In fact, there is no such option.

I am working with iPadOS betta 14.7

What seems to be happening is that the website thinks you are using Safari for macOS and in reality you are using Safari for iOS which uses the same rendering engine but is entirely different in the way it lets you set the media handing.

In fact I didn't see any setting for auto play here:

Settings > Safari

Settings for iOS apps are almost always in the Settings app. The Apple (built-in) apps all have their settings there.

What I did see what an option for "Request Desktop Website."

It might be that is on and it may need to be off for this particular website to work properly. If it is on turn it off and the website will then realize that you are on an iPhone and switch the content around to be optimized for a mobile device.

It is also possible that you ran into a bug in the beta software you have installed on your phone, that there is no fix for until (maybe) the next beta release.