why my face time show chose another number or email adress to call a person

Hi Rana_03

welcome to the Apple (user-to-user) Community.

Seems FaceTime needed to use the contact info. that is supplied in the Contacts app, to make that call:

There may be restrictions in place for the calls you can make on FaceTime:

Eg: Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support

or

Set up Screen Time for your child - Apple Support

Else: As your screenshot suggests:

For FaceTime calls to that person, try updating the details on their contact card to allow FaceTime calls:

Eg: In the Contacts app:

✽ Tap the contact's name, then tap Edit.

✽ Enter or update their contact information (ie: to allow FaceTime calls)

✽ When you’re finished, tap Done.

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OR you may not have to use the Contacts app:

More ways to make FaceTime calls (from: How to: Use FaceTime with your iPhone or iPad - Apple Support

✽ "In the FaceTime app, tap New FaceTime and type the person's phone

number or email address. Tap the number or address, then tap the Audio

button  or   FaceTime.

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✽ If you have the person's phone number or email address saved in your Contacts,3 

you can start typing their name and tap the name when it appears. Then tap the Audio button  or  FaceTime.

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✽ You can also start a FaceTime video call from your iPhone during a phone call.

Tap the FaceTime icon in the Phone app to switch to FaceTime."

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More info. / support / contact:

FaceTime Support website:

FaceTime - Official Apple Support

All the best :-)