First, please read this post and give us ALL the information requested there. At the moment we know nothing about your computer nor even the version and variant of MEP you are using.
Then, I suspect it might be helpful if you could take a screenshot of your timeline when MEP is open and attach it to your next post. That will allow us to see exactly what you are seeing and so suggest possible solutions to your problem.
As a general suggestion for when you seem to "lose" something on the MEP screen, pressing F9 will restore the window to its default settings.
Hmm, interesting. What I see when I try to do the same as you, i.e. apply Brightness and Contrast to a clip:
You will see I have rather more options under the Brightness tab AND the keyframe screen is visible! (Don't worry about the fact that the left hand side of the screen, where the different options are shown, is different to yours. I simply chose a different view option; you have Tiles, I have a simple list).
The only assumption I can make is that you are actually running the Basic version of MEP. My screenshot below is of MEP Premium. The current version is as shown on my screenshot. Can you check exactly what yours says, under Help>About Magix Movie Edit Pro, especially what it says about the actual variant you have, whether Basic, Plus or Premium?
HTH
Jeff
UPDATE: beaten by John EB, with the obvious answer!
Your first screenshot shows that you are actually running MEP 2018 (that is version 17) but that you are at least one patch update version behind. So first, please use Help>Check for Updates, though it is possible that your Update Service has now expired.
You won't see the keyframe bar unless you have a video object on the timeline AND have selected an Effect to apply.
. . . . Thanks i tried everything that you said but nothing works i don't know what els to do . . . .
Without a screen shot of the problem showing the following:
An image or video on the timeline and is selected and you have the Effects tab open with View/animation, Size/position selected and showing the dialog box.
I suspect that this is what you are seeing/not seeing: