Picture works, I think you might struggle as they look like they might have once had a nut on the back, and in undoing the screw, the nut has fallen off and is now either in the bottom of the cooker or gone.
Not the end of the world, if you or someone you know is competent to take the back of the cooker off you can use any nut and bolt that fits through the hole (relatively short bolt).
And the two missing screws on the right hand side in your picture are important. That is the earth connection from the supply to the cooker's case.
So that must be securely in place before using the thing!
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