Hello
First thing I would do is check what power that motor has.
I would presume a thin kerf blade would be needed for that machine, not a 3.2 kerf blade.
Your riving knife should to be wider than the saw plate, but narrower than the teeth, somewhere in between.
If you have a thin kerf blade of correct size, I have seen some in Aldi, although have no experience with using anything but a proper blade, is to get some stiff cardboard to make up a template from.
You might have some guage plate or a bit of stainless the right thickness knocking about somewhere, and cut it out with an angle grinder.
Steve Maskery has noted that a captured knife is safer, meaning that you can't pull it out and have to unbolt it.
Failing that..
I would guess if you looked up a Clarke tablesaw you might find it could be the same model and hopefully it might have the same or a very similar model number,
so you could google for spares.
Tom